Review Index:

Samsung 840 EVO Performance Restoration Tool preview - Getting EVOs back up to speed

Subject: Storage
Manufacturer: Samsung


** Edit **

The tool is now available for download from Samsung here. Another note is that they intend to release an ISO / DOS version of the tool at the end of the month (for Lunix and Mac users). We assume this would be a file system agnostic version of the tool, which would either update all flash or wipe the drive. We suspect it would be the former.

** End edit **

As some of you may have been tracking, there was an issue with Samsung 840 EVO SSDs where ‘stale’ data (data which had not been touched for some period of time after writing it) saw slower read speeds as time since written extended beyond a period of weeks or months. The rough effect was that the read speed of old data would begin to slow roughly one month after written, and after a few more months would eventually reach a speed of ~50-100 MB/sec, varying slightly with room temperature. Speeds would plateau at this low figure, and more importantly, even at this slow speed, no users reported lost data while this effect was taking place.

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An example of file read speeds slowing relative to file age.

Since we first published on this, we have been coordinating with Samsung to learn the root causes of this issue, how they will be fixed, and we have most recently been testing a pre-release version of the fix for this issue. First let's look at the newest statement from Samsung:

Because of an error in the flash management software algorithm in the 840 EVO, a drop in performance occurs on data stored for a long period of time AND has been written only once. SSDs usually calibrate changes in the statuses of cells over time via the flash management software algorithm. Due to the error in the software algorithm, the 840 EVO performed read-retry processes aggressively, resulting in a drop in overall read performance. This only occurs if the data was kept in its initial cell without changing, and there are no symptoms of reduced read performance if the data was subsequently migrated from those cells or overwritten. In other words, as the SSD is used more and more over time, the performance decrease disappears naturally.  For those who want to solve the issue quickly, this software restores the read performance by rewriting the old data. The time taken to complete the procedure depends on the amount of data stored.

This partially confirms my initial theory in that the slow down was related to cell voltage drift over time. Here's what that looks like:

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As you can see above, cell voltages will shift to the left over time. The above example is for MLC. TLC in the EVO will have not 4 but 8 divisions, meaning even smaller voltage shifts might cause the apparent flipping of bits when a read is attempted. An important point here is that all flash does this - the key is to correct for it, and that correction is what was not happening with the EVO. The correction is quite simple really. If the controller sees errors during reading, it follows a procedure that in part adapts to and adjusts for cell drift by adjusting the voltage thresholds for how the bits are interpreted. With the thresholds adapted properly, the SSD can then read at full speed and without the need for error correction. This process was broken in the EVO, and that adaptation was not taking place, forcing the controller to perform error correction on *all* data once those voltages had drifted near their default thresholds. This slowed the read speed tremendously. Below is a worst case example:

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We are happy to say that there is a fix, and while it won't be public until some time tomorrow now, we have been green lighted by Samsung to publish our findings.

Continue reading our look at the new Samsung 840 EVO performance restoration process!!

October 14, 2014 | 07:46 PM - Posted by lantian (not verified)

thanks for the update

October 14, 2014 | 07:48 PM - Posted by Robogeoff (not verified)

Allyn, So is it safe to buy a Samsung 840 Evo again? Or would you recommend another brand/model instead?

October 14, 2014 | 07:53 PM - Posted by Anonymous (not verified)

Would like to know the same thing.

I like Samsung EVO SSD's but was on the fence to hold off.

Should I go Crucial which I've never owned or buy Samsung again?

October 14, 2014 | 07:57 PM - Posted by Crazycanukk

Nah..Samsung has said they have been able to replicate the issue and are actively working on a fix. you'll be fine going with the Samsung drives + its not a defect in the drive itself..its just an issue in how the software and error correction handles the data after a while they need to fix.

+ its not an issue on all models of Samsung SSd's either.

October 15, 2014 | 11:51 AM - Posted by Anonymous (not verified)

Just grab mx100 and call it a day. Its a better option overall ever since it came out.
Its faster, cheaper, MLC flash !!!, partial powerloss protection.

I really dont get why people still buy EVOs. You're pretty much just paying more money for a inferior drive, just because it has a fancy samsung sticker on it and was once a good buy.

October 15, 2014 | 12:03 AM - Posted by Allyn Malventano

I've always recommended these for their balance of price and performance. I paused that recommendation until we knew there was an update coming, but now that it's out and appears functional, I'll recommend them and revisit after we've had data sitting on these drives for a few weeks.

October 15, 2014 | 09:22 AM - Posted by Robogeoff (not verified)

Thanks for keep on this Allyn. I'll keep holding off for a verdict.

October 15, 2014 | 11:52 AM - Posted by Anonymous (not verified)

Grab mx100 :)
Why pay more for less ?

October 15, 2014 | 10:24 PM - Posted by razor512

It has even worst write endurance than the 840 evo

October 16, 2014 | 02:38 AM - Posted by Allyn Malventano

MX100 performance is not great at smaller capacities. An 840 EVO 120GB walks all over an MX100 128GB, especially in write speeds.

October 15, 2014 | 10:18 PM - Posted by razor512

The EVO's are a worst value compared to higher end SSD's such as the pro series when you consider the price you are paying, and how many TB of data the drive can handle in writes before it begins to fail.

The EVO's pretty much begin to rapidly burn through the over provisioned cells after about 100TB Due to the uncertainty of how an SSD will handle a failure state, in terms of reliability, the SSD is pretty much gone at this point, MLC drives can often handle 5 to 10 times that amount.

Also keep in mind that even though SSD's have spare sectors, they are still used during wear leveling, this means that when a few cells start to fail, you can bet that all of the cells are pretty close to their limits which is why you see on the tech report article, the SSD's will handle many TB with no problem but at one point you suddenly start to get a ton of reallocated sectors before the SSD randomly dies.

If you regularly do video editing using programs like adobe premiere pro, expect to put 40+ TB of writes to your SSD each year, even if your source videos are on another drive due to how these programs cache working data. (And moving the cache to a different drive is not an option as it defeats the purpose of using an SSD).

October 16, 2014 | 02:36 AM - Posted by Allyn Malventano

Not sure if you are aware, but 840's (not Pro) have been tested to nearly a petabyte in actual use, so given your usage figure, one would last well over a decade.

October 14, 2014 | 07:54 PM - Posted by Crazycanukk

Thats Great News and thanks for the update :)

I just built a new system with a 1Tb 840 Evo for games and and some light file storage and after i heard the news of performance loss on the Podcast i got nervous. This is good news.

One another Note i must thank-you again for the suggestion on the podcast about the Drivefresh software. I have used it on 3 systems i own and the 3 drives that i use to store data long term locally. (i have 2 other offsite storage solutions as well). Just a word of warning to those getting it ..the free home user version works very well to "refresh" your data on the HDD but it takes many hours to 1 system with a 1.5 Tb drive full of movies and pictures took over 20 hours to complete.

October 14, 2014 | 08:06 PM - Posted by odin (not verified)

Do you know if it is possible to run the tool on a 840 EVO using bitlocker under windows 7 x64?

I already run diskrefresh once and everything went fine, but maybe Samsung is using a different approach that could have issues with a bitlocker-encrypted drive.

October 15, 2014 | 12:05 AM - Posted by Allyn Malventano

The tool doesn't support RAID or dynamic disks, so bit locker is probably unlikely. Anyone running in non-standard configurations should seriously consider emptying the EVO and applying the update in a simple partition / format state.

October 19, 2014 | 06:44 AM - Posted by Anonymous (not verified)

I ran it on a Bitlocker encrypted drive and it worked fine.

October 14, 2014 | 08:18 PM - Posted by Spacebob (not verified)

Glad to hear Samsung has got a fix and that it works!

I'm curious how the firmware update works. Is this something that the tool does automatically? In the past, on my ASUS M5A99FX PRO R2.0 I had to create a USB boot drive to flash the firmware to the drive. I thought this was because the Samsung Magician tool didn't work with AMD chipsets. Is this no longer an issue?

October 15, 2014 | 12:06 AM - Posted by Allyn Malventano

Per their documentation, it should work under AMD, but only with their newest driver, or by reverting back to the MS AHCI driver.

October 14, 2014 | 08:21 PM - Posted by jchambers2586

I am using RAID0 is RAID supported?

October 14, 2014 | 10:33 PM - Posted by Rick (not verified)

I'm in your boat, raid 0 two 250 evos. I don't feel like doing a clean install.

October 15, 2014 | 01:50 AM - Posted by wiak (not verified)

FYI, raid people, image your array, then update each ssds and then setup raid again and restore image...

if you dont have a external hdd for data, get one...

Macrium Reflect can do this

October 15, 2014 | 04:11 PM - Posted by Allyn Malventano

I added the sequence you'd have to follow to the middle of page 2.

October 14, 2014 | 11:56 PM - Posted by Fred (not verified)

does not work on drives connected to raid, must be ahci, at least according to

October 15, 2014 | 12:07 AM - Posted by Allyn Malventano

No go on RAID or dynamic disks.

October 14, 2014 | 08:34 PM - Posted by Anonymous (not verified)

Thank you Allyn!

October 14, 2014 | 09:47 PM - Posted by Paul Thomsen

You guys need a Like button. It's articles like this that keep us coming back to PCper

October 15, 2014 | 01:13 AM - Posted by Anonymous (not verified)

Please, no. This isn't Facebook and it doesn't need to be.

October 17, 2014 | 03:14 PM - Posted by DrWattsOn


October 14, 2014 | 09:48 PM - Posted by Paul Thomsen

(but it's too easy to double-submit comments)

October 15, 2014 | 12:08 AM - Posted by Allyn Malventano

Apologies. We are working on crushing that bug, but it may get rolled into a complete site update.

October 14, 2014 | 10:15 PM - Posted by John Blanton (not verified)

So when are we going to be able to get our hands on the restoration tool? Can any of the pcper guys post a download link?

October 14, 2014 | 10:59 PM - Posted by Anonymous (not verified)

"We are happy to say that there is a fix, and while it won't be public until some time tomorrow, we have been green lighted by Samsung to publish our findings."

October 14, 2014 | 10:52 PM - Posted by Anonymous (not verified)

Does this include 840 Pro models or is it specifically 840 EVO?

October 15, 2014 | 12:09 AM - Posted by Allyn Malventano

Pro is not affected, but many have seen this same slow down on the original 840 (which is also TLC).

October 15, 2014 | 01:52 AM - Posted by wiak (not verified)

agreed, i have a pair of 840 pros and they are NOT affected, but allyn do you know if 840 EVO mSATA is affected or not?

October 15, 2014 | 01:54 AM - Posted by wiak (not verified)

and yes i also have a 840 120GB (the old non-evo/non-pro series) and its affected

October 15, 2014 | 04:14 PM - Posted by Allyn Malventano

MSATA EVOs are effected, and will update with the same tool. We just confirmed this here.

October 14, 2014 | 11:25 PM - Posted by Mandrake

Thanks for the update Allyn. Samsung has only mentioned the 840 EVO, does this not apply to the vanilla 840 too? They're both TLC SSDs. My system has a 500GB Samsung 840 in it, though I seem to be lucky enough to have not had this issue.

October 15, 2014 | 12:10 AM - Posted by Allyn Malventano

Some with the standard 840 have reported the issue, but Samsung has not confirmed that, so the best I can say is keep an eye on it in the future.

October 14, 2014 | 11:32 PM - Posted by Anonymous (not verified)

"Out of five drives we tested the process on, one of them corrupted its MFT during the post-reboot process, and a subsequent reboot resulted in the loss of nearly all data."

Uh... that's kind of a BIG deal.

October 15, 2014 | 12:20 AM - Posted by Allyn Malventano

I agree, but this is probably the most technically difficult update process I've seen for any device. The fact that Samsung was able to put this functionality into a tool that can rearrange data at the flash block level behind the OS's back, even while that OS is installed on the very drive being manipulated, is no small feat. The drive that errored was nearly filled to capacity with steam downloads (which heavily fragments the flash given the way Steam writes downloaded game data). I had emptied just enough of it to get the update to run. If users are more conservative with their preparations for this update, they should be fine, especially if they have backed up prior to running it.

Also note, the drive was not bricked, it just need to be reformatted (to be conservative) because of the corruption. I chose to repartition it, as that forces the whole drive to be TRIMmed.

October 15, 2014 | 07:59 AM - Posted by Topinio

Yes, it's no small feat. Can you comment on whether the tool works on a non-system drive basis, i.e. can one use another system to fix these drives?

That should be safer, and ideally it would be possible to fix multiple drives simultaneously.

October 15, 2014 | 04:29 PM - Posted by Allyn Malventano

Yes it works on EVOs connected as a secondary drive (that's what we did for testing), but you must complete the full sequence (including the shutdown/power cycle) on each drive before moving onto the next.

October 16, 2014 | 08:41 AM - Posted by ablatt

If the tool "can rearrange data at the flash block level behind the OS's back, even while that OS is installed on the very drive being manipulated" then why does it need NTFS on it in order to run?

October 16, 2014 | 08:42 AM - Posted by ablatt

If the tool "can rearrange data at the flash block level behind the OS's back, even while that OS is installed on the very drive being manipulated" then why does it need NTFS on it in order to run?

October 15, 2014 | 01:56 AM - Posted by wiak (not verified)

makes sense to backup? i learn that the hard way updating firmware on a hard drive years ago

soo remember kids, backup before firmware upgrading

October 14, 2014 | 11:59 PM - Posted by collie

Big question, Does this help the same problems with the non evo 840? same problem, so same update or not?

October 15, 2014 | 12:11 AM - Posted by Allyn Malventano

We're still working on an answer to that one.

October 15, 2014 | 01:10 AM - Posted by Anonymous (not verified)

did this issue exist on the msata 840 evo

October 15, 2014 | 01:20 AM - Posted by Allyn Malventano

Yes, and the same update will correct the issue as well. MSATA is only a packaging difference. The drive itself functions identically.

October 15, 2014 | 01:58 AM - Posted by wiak (not verified)

thx for the heads up

October 15, 2014 | 02:30 AM - Posted by Sven (not verified)

Well i got 750GB 840 EVO in my iMac, in my Macbook and a 250GB in my PS3.
What about those users? How will/can they update their drives, any informations on this?

October 15, 2014 | 10:29 AM - Posted by collie

Oooooo, that's a doosie of a problem, one that alot of us never thought of, and I doubt that Samsung is even working on that. You did install the ssd's yourself right? I suppose the only actual way would be to remove the ssd's (and I know how hard that is on a Macbook, so so sorry) install them on a pc (perhaps there is one you have accesses to, a parent or a friend or even an old dusty rig sitting in storage) and do the update that way. If the ssd is factory installed my apple then apple will be the one sending you the update, but that's probably not the case. Personally I hate opening up anything apple, whatever I would have to pay someone else to do it would be well worth it.

October 15, 2014 | 10:33 AM - Posted by collie

Now that I think about it, there might be a simpler soloution. Just a guess but perhaps you could do a full backup, format, install windows, update the drive, format, then restore. Still not simple but it might be the easiest answer, if it works, like I said just a guess. The PS one tho, that;s gona need to be put in another system for sure.

October 15, 2014 | 04:30 PM - Posted by Allyn Malventano

A partition agnostic ISO/DOS version of this updater will be out at the end of the month. That should work on everything else, but you really should image / back up those drives first, just in case.

October 16, 2014 | 05:44 PM - Posted by collie

well that just makes every thing SO much easier, thanks for poking them Allyn. Still no word on vanilla 840's yet eh?

October 15, 2014 | 02:40 AM - Posted by LarryM7 (not verified)

Just stick them in a pc and do the job. It's a bit of a hassle but it's for once.

October 15, 2014 | 03:50 AM - Posted by Sven (not verified)

"Just Stick them in a pc" : i do not have any pc and it is also not easy to get the drive off the iMac, since it involves display disassembly on those, so this cant be the solution for Mac users.

October 15, 2014 | 04:31 PM - Posted by Allyn Malventano

Mac updater due out at the end of the month.

October 15, 2014 | 03:09 AM - Posted by Suraj Deuja (not verified)

What about people who've installed this drive on a macintosh?

October 15, 2014 | 03:33 AM - Posted by Charlie Pearce (not verified)

Thanks for the update Allyn.

Any idea if this tool will be available on anything other than Windows?

My main system runs an 840 with Linux, and also have two 840 users with Macs. I can feel some reimaging coming on....

October 15, 2014 | 05:50 AM - Posted by Jørgen (not verified)

Will be released on end of Oct.

October 15, 2014 | 08:32 AM - Posted by Charlie Pearce (not verified)


October 15, 2014 | 08:56 AM - Posted by picchitta (not verified)

Anyone knows whether is possible to update the firmware by using in a Macbook a second HD where there is installed Windows in bootcamp?

October 15, 2014 | 09:28 AM - Posted by Anonymous (not verified)

can I do this on an external usb drive?

October 16, 2014 | 02:42 AM - Posted by Allyn Malventano


October 15, 2014 | 10:39 AM - Posted by Anonymous (not verified)

the link with the long awaited firmware update :-)

October 15, 2014 | 11:30 AM - Posted by Anonymous (not verified)

Is this for one time only, or I must run this program again after some time - can I uninstall Performance Restoration program after applying the fix?

October 15, 2014 | 02:16 PM - Posted by cyberwire

Did you read the article at all?

October 15, 2014 | 02:18 PM - Posted by cyberwire

from page 2:
"Once the tool completes the full procedure on an SSD, there is no way to repeat the process. You can’t even restart the process on a given SSD as the option is greyed out. This is meant to be a one way trip, and should permanently correct an updated EVO moving forward. Once you’ve updated, you can safely remove the software as it is no longer needed."

October 15, 2014 | 11:38 AM - Posted by Pieter (not verified)

My 840 EVO is my Hackintosh's boot disk. It's main partition is HFS+, using GPT. I was thinking of running this tool from my separate Windows disk.

Would it matter that the drive's main partition wasn't formatted NTFS? The user guide says NTFS is a requirement.

October 15, 2014 | 04:33 PM - Posted by Allyn Malventano

Not sure how the updater handles mixed partitions. To be safe, I would hold out for the ISO/DOS based updater, due by the end of the month.

October 15, 2014 | 02:13 PM - Posted by kaikane (not verified)

Hey guys, so i used the tool but i dont think it solved anything...i ran HD Tach and results still scatter between 250 and 500GB\s...Samsung 840 EVO 250GB. Has anyone experienced the same result?

October 15, 2014 | 06:15 PM - Posted by Wade (not verified)

Ran the Samsung restoration tool and WOW I could not believe what a difference it made on my 840 EVO 750. THANKS for the article Allyn.

October 15, 2014 | 06:57 PM - Posted by Elbstrand

Initial benchmark of my 840 EVO 250gig and also the benchmark graphic in this very post, show that read speeds are down to 350mb/s also my write speed seem to be slightly down to 450mb/s. Can anyone confirm that? Any idea why?

Before the firmware update benchmarks where about 450-520 on both read and write.

October 16, 2014 | 03:17 PM - Posted by Allyn Malventano

Those are actually typical figures for an actively used / filled SSD.

October 15, 2014 | 11:38 PM - Posted by CrisisHawk

Ryan mentioned on the podcast that this will not work for standard 840 drives, but it is mentioned in the user guide, can anyone confirm one way or the other?

October 16, 2014 | 12:00 AM - Posted by Kingkookaluke (not verified)

Yeah! Now I really want to win that car!!!

October 16, 2014 | 01:52 AM - Posted by Nick Eslinger (not verified)

Mine gets stuck at 40% on step 2. I've ran it multiple times and it always gets stuck, I left it there for an hour. I have the 1TB model and 202GB free. Can anyone tell me why it's doing this and what I can do to make it work?

October 16, 2014 | 01:58 AM - Posted by Nick Eslinger (not verified)

Nevermind, I ran it again and it's working fine this time, must have just been a random occurrence.

October 17, 2014 | 03:01 AM - Posted by Wijkert

After applying this fix to my 750GB evo, my average read speed went up from 317mb/s to 541mb/s. Used SSD Read Speed Tester mentioned in the first article. Time will tell if this fix is a permanent solution.

October 16, 2014 | 10:07 AM - Posted by Anonymous (not verified)

But if you have installed your Windows OS in desktop RAID mode, that is SATA mode in the BIOS is set to RAID and not IDE or ACHI, currently, there is no solution.

In desktop RAID PCs setting SATA mode to IDE or ACHI renders any drives unreadable, as there is no IDE or ACHI drive and you risk losing your data.

October 16, 2014 | 11:30 AM - Posted by Anonymous (not verified)

Wow that was a dramatic improvement!

October 16, 2014 | 12:11 PM - Posted by Ghostmop

I ran the Performance Restoration Tool on my 840 EVO 1TB drive last night. I did not experience any problems with the tool. I installed the SSD in late May 2014, so I don't think I was experiencing any slowdown issues.

October 16, 2014 | 01:29 PM - Posted by Juni0rm1nt (not verified)

Thanks for the very informative article. I was able to update both my EVO's with no problem.

Keep up the good work.

October 16, 2014 | 04:08 PM - Posted by Anonymous (not verified)

Does this tool support the samsung tlc enterprise models: 845DC EVO, the PM853T(oem version of 845DC EVO) and the PM843? They haven't been out long enough to test if they had the leaky tlc issue yet.

October 16, 2014 | 04:46 PM - Posted by JohnnyR

i have not gone through with the firmware update but after i installed what i think is the tool linked in the post. the tool asks me to clone my C drive. is this what everyone had to do?

October 16, 2014 | 09:19 PM - Posted by Kingkookaluke (not verified)

I didn't have to do that. Or rather didn't see it asking me to do that.
I did try to migrate from one ssd to the spare ssd ,and the software can not see the other 840 Evo for some reason. It could have something to do with the trim.

October 16, 2014 | 09:00 PM - Posted by Branthog

Kind of frustrating that the stupid piece of software they want me to constantly run on my OS (the Samsung SSD Magician or whatever) can't just update the firmware for me and I have to separately go download and install.

God damn, that website. Samsung, are you stuck in 1994?

October 31, 2014 | 07:59 AM - Posted by Fabiano G. Souza (not verified)

I agree wholeheartedly.

October 16, 2014 | 09:04 PM - Posted by Kingkookaluke (not verified)

I still have some files that drop in speed.. What up wiff dat?

Also, I really want to win that car!!!

October 16, 2014 | 11:07 PM - Posted by Leign

will try this coming weekend.. 840 EVO 250GB

October 19, 2014 | 09:12 PM - Posted by Leign

success!!! no data loss.. thanks PCper for this info.

October 17, 2014 | 05:55 AM - Posted by Pimmsley (not verified)

I just cloned and pulled an 840 120GB (non pro, non evo) from a business mission critical machine after reading this article until this bl**dy mess is sorted out :(
Yes I do perform weekly backups, but arrrrrgh...
I'm very dissapointed as I had already swapped out an OCZ drive from said machine with the 840 as I was paranoid about the OCZ failling... here we go again... I had bought two 830's, and after the reliability of those thought the 840 series would be just as rock solid...
So I guess I need to find another drive, again.

Please persue the 840 (non pro, non evo) issue with Samsung Allyn, many of us still use them and would like to fix them... if there is no fix coming for it I would like to know so I can try and return the 840 to samsung.
I am still shocked that it's not 100% clear if the 840 is affected by this slow down bug. If people are indeed reporting issues with the 840, then why hasn't Samsung confirmed it and provided a fix for those too ???
There must be hundreds of thousands of them out there, right ?

Love the PC Per Podcast and thanks for the diligent reporting, just don't forget about us poor non evo, non pro, owners. ;)

October 17, 2014 | 11:55 AM - Posted by George Lamson (not verified)

Tried using the restoration tool for my 250 Gb evo 840 in my Dell XPS 8300. It started up and ran up to 15% complete and then just stopped. I let it run overnight and still stuck at 15%. There was a comment in red that said the tool wouldn't work with 3rd party disk managers. I wasn't sure if that was an error message or just inofrmation. I am running win7 and it is has all current updates and drivers. I believe there is an Intel storage manager running somewhere on the system.

I didn't want to try it again until I checked to see if anyone else is running into similar problems.

Anybody run into this?

October 18, 2014 | 11:57 AM - Posted by George Lamson (not verified)

I have tried several times now to get the restoration tool to work. The same thing happens every time. It runs for about 15 minutes on the first task, updating the firmware and then fails with an X next to the firmware update. I'm not doing anything special and my rig is pretty vanilla Dell. Not sure what to do at this point?

October 20, 2014 | 02:15 AM - Posted by ccn (not verified)

I have two 500gb 840EVO m.sata drives in a startech msata to 2.5in sata converter. Controller is set to JBOD.

I was able to update the firmware in one drive. With the other drive, the 840 Restorer program gets to 15% and stops working.

October 20, 2014 | 01:11 PM - Posted by Allyn Malventano


The updater halts at 15% if it can not update the firmware. Best bet is to be sure you are in AHCI mode. Worst case, hold out for the ISO based updater, which is due out by the end of the month.

October 17, 2014 | 12:16 PM - Posted by Fotis (not verified)

I bought the 120gb 840 EVO a few days ago and installed windows 8.1 on it. It has the previous firmware. Do I need to update to the newest firmware and run the restoration tool or just do the firmware update?

October 20, 2014 | 01:13 PM - Posted by Allyn Malventano

The whole process is needed to ensure you get full speed over time moving forward. The additional steps do more than just shuffle data - they reinitialize some of the flash parameters.

October 20, 2014 | 03:24 PM - Posted by Fotis (not verified)

Thank you for the reply!

October 17, 2014 | 03:12 PM - Posted by Materialsguy (not verified)

Hey Guys,

Just finished running the Restoration Tool on an 840 EVO, 256 GB. It works as advertised; the only hiccup was that I had to resize my swap file to hit the 10% space requirement. Here are the numbers:

Before Restoration : 90 - 240 MB/s read speed, BIG variation
(using HD Speed)

After Restoration 508 - 540 MB/s read speed with very little variation (using HD Speed)

The process took about 1 hour on the drive, which is about 75% full (without the swap file)

Thanks for the video.

Shaun M.

October 17, 2014 | 04:25 PM - Posted by DrWattsOn

from original thread, … …
October 10, 2014 | 06:03 AM - Posted by DrWattsOn

It may do us well to keep an eye on the 850 Pro. It still uses TLC but maybe their claim that the 3D Vertical stacking "locks in" the bits, fixes the problem? I think they also use a thicker process that would help the bits to remain at their original levels and need less error correction. Maybe better R/W longevity too? Any ideas??

October 20, 2014 | 02:00 PM - Posted by Allyn Malventano

I think they meant 850 EVO, because the Pro uses MLC.

October 17, 2014 | 05:07 PM - Posted by Engell (not verified)

Did the update on my 500GB 840 EVO.. everything was ok afterwards, think it took about 40minutes on my laptop.

Here are images from my benchmarks before and after. Top images are after the firmware upgrade, and the lower images are before the upgrade.
HD-Tach / Crystal Diskmark 64 bit / Samsung Benchmark

October 17, 2014 | 07:47 PM - Posted by dlpatague (not verified)

I have a question. I need at least 1TB of drive space, but don't really need anymore than that as that should be plenty. Should I RAID 0 two Crucial MX100 512GB SSDs which right now on Newegg are $209.99 each? Or should I get a single Samsung 840 EVO 1TB which is $424.99 right now? Or should I wait and see if Samsung releases an 850 EVO to see how prices change? What are these drives used for is pure gaming storage! The OS is running on a two drive Intel 320 120GB RAID 0. So this is not a mission critical rig.

October 17, 2014 | 08:14 PM - Posted by Kingkookaluke (not verified)

My first instinct is to tell you to go with the single drive. You will not have bios update issues, or too many, if you stick with the single disk set up. If you chose to Raid 0 ,you'll have to break the raid to run the bios updates on both of those disks.

That being said, I have recently purchased yet another 840 Evo (1TB), and I plan on running them in raid stupid by this weekend. I understand that the spread out of the reads/writes basically boosts drive performance. If I don't realize the performance increase I will just switch back to the single drive set up. I also use my initial 840 as my OS drive.

Samsung has already released the 850 Pro, and based on the sales of the 840 Evo they would be stupid not to follow down that path again.

I hope this response offers you some direction. At present I say go with the one drive.

October 20, 2014 | 07:02 AM - Posted by Reto G. (not verified)

It seems you guys know this SSD disk very well! May I ask you a deep-dive question related to the Samsung EVO 840 1TB:

What is the "Block-Size" on this type of disk? 4k or 8k?


October 20, 2014 | 01:54 PM - Posted by Allyn Malventano

It has'nt been published for this type of flash, but it's likely 8KB pages and 1MB blocks.

October 20, 2014 | 08:25 AM - Posted by TigerClaw (not verified)

Is this only affecting the 840 EVO SSDs, And not the Non Pro and Pro versions?

October 20, 2014 | 01:55 PM - Posted by Allyn Malventano

The Pro is immune. The 840 (not Pro or EVO) does seem effected, but has not been acknowledged as such by Samsung.

October 20, 2014 | 03:08 PM - Posted by TigerClaw (not verified)

That's good to know, I been using the 840 Pro 512GB SSD for quite sometime.

October 20, 2014 | 03:08 PM - Posted by TigerClaw (not verified)

That's good to know, I been using the 840 Pro 512GB SSD for quite sometime.

October 20, 2014 | 03:26 PM - Posted by Juni0rM1nt (not verified)

Out of a topic but rather annoying and it has been bugging me for quite some time.. How do I disable the Samsung Magician software that launches at start up? This happens with both Windows 7/8. I could disable it in the older version of magician but not quite sure how to with the newer version.. Thanks.

October 21, 2014 | 06:12 PM - Posted by ablatt

It gets started in the Task Scheduler. Click on Task Scheduler Library and you'll see it there set to load on startup.

October 20, 2014 | 04:52 PM - Posted by Dusty

How did you measure the power consumption of the SSDs? Is that a Windows utility?

October 21, 2014 | 03:16 PM - Posted by Anonymous (not verified)

FYI to anyone wondering. I have a Samsung 840 EVO 1tb drive as my boot drive (win7 x64). I have the SATA controller in my system configured as RAID because i have a couple 2tb data drives in a Raid1 mirror. I was unsure whether the Performance Restoration utility would work on my system as the release notes state it only supports AHCI mode.

I'm happy to report the Performance Restoration utility worked fine on my system. It took a couple hours, but completed successfully. Hope this helps anybody else that is in the same situation where the Sata controller is configured as RAID, but the ssd itself is not in a Raid array.

October 23, 2014 | 07:49 PM - Posted by Anonymous (not verified)

What is your RAID controller?

October 21, 2014 | 10:37 PM - Posted by Mark_GB

Even with this bug, Samsung has been the most reliable SSD out there. Bar none.

I have owned a 1TB 840 EVO since April. I use the system extensively, and the 840 EVO is my only "drive". I took the time this afternoon to go download the software, and ran it. It updated the BIOS and then shut the system down. I waited a bit, restarted it, and watched as it proceeded with the first of the three steps. I then left for a meeting. When I got back an hour later, it was done. Just to feel better about things, I closed out the program, and shut down. Waited a bit, and powered back up. It came right back up and everything is working just fine.

I have never lost any data, and while I kind of suspected at times that the drive might not be as fast as it was when I first got it, I kind of put that to the fact that there are hundreds of megabytes of data on this drive, and that it has been used a lot, and that it had probably reached it stable state speeds. Then a couple months later, I heard about this bug and kinda laughed.

Tonight, I loaded some large files for the first time in a week, and while I haven't timed anything, I noticed that they loaded lots faster than they have been. So I am happy, and I would buy more Samsung drives any day of the week. They are the only SSD maker out there that produces everything in the SSD itself. And their track record is just fantastic.

October 22, 2014 | 12:57 AM - Posted by Pimmsley (not verified)

Settle down there fella... Tell that to the 840 'vanilla' owners, like me... Samsung hasn't even acknowledged there is a problem and no tool to fix our drives :/

...and I have personally bought 3 Samsung SSD's (2x 830 and 1x 840 non pro, evo)...

A fair point raised over at Overclockers is that if the Samsung restoration tool is just shifting data about, that's not a true indication that the problem is indeed fixed...
Pity we don't know what the firmware update is really doing moving forward...
I hope they I would like to see performace figures in a few - more months to prove it really has been resolved.

October 22, 2014 | 11:15 AM - Posted by SirWithrow

What's the best way to image my drive, and it has to be free cuz im broke?

October 22, 2014 | 09:33 PM - Posted by dummergold (not verified)

Thanks guys - a Samsung pop-up on my machine alerted me to the restoration software. Youtube led me to you two which enforced the process.

Firstly I started with my operating system 500GB EVO 840. Back-up, yes, cloned through Samsung Data Migration - I was uneasy at how it looked at the 270GB as 199GB. I cloned it out, disconnected the original OS, and ran on the cloned OS. Seemed to be fine, but what really confused me was that the EVO 840 1TB that I cloned the 199TB to, became somewhere into the 600TB. Well, seemed weird to me, but I had seen that before with the original 500GB EVO SSD when it was first initialized and Windows being installed with all fresh programs - there were far more GB showing then actually downloaded. I filed it as weird and moved on.

What I am getting at is ' Why would Samsung Data Migration see less GB then what Windows/My Computer sees? But this isn't about Data Migration, just a process before the Performance Restoration.

My EVO 840 500GB Performance Restoration just became 100% complete. Now I have four more 1TB EVO 840's and one 250 EVO 840's to do.

I'd say the 500GB took less then an hour for the Performance Restoration (I should have timed it).

Sorry, I won't be able to tell you the speed spec's, I will be just going by feel and will not know until I have all the EVO's done. Then I will dig back into a project and see.

I say thanks - your video and comments page are a big asset. Keep up the good work.

October 22, 2014 | 11:34 PM - Posted by Anonymous (not verified)


Just wanted to say that this procedure works fine on a MacBook in Windows from the bootcamp partition.

This is on a 500GB Samsung 840 EVO.

Updated my backup one last time and booted my Win 8.1 bootcamp install.

Installed the samsung performance restoration tool, reverted my AHCI driver to the stock windows one and rebooted for safety and compatibility reason.
On the apple boot screen, I set the Windows partition to be the default boot option as I knew there was a few reboots needed.

HFS+ partition had 282.63GB out of 330GB free
NTFS partition had 83.69GB out of 170GB free

Booted Win 8.1, launched the tool, clicked start, firmware was flashed and windows shutdown the computer.

Powered it up again, Windows booted, I logged in, the tool started up again automatically and continued the process.

After about 90minutes it completed. I closed the tool and rebooted Windows, already the boot time was shorter than it had been in quite some time. Logged in and uninstalled the tool as it was no longer needed. Also reverted the AHCI driver back to the last compatible Intel RST for my chipset which happens to be 12.9.

After confirming that Windows still boots with RST now in place, I rebooted the system once more and restored the HFS+ partition as the default boot option and booted OSX.

This also booted faster than it had done so in quite some time.

Tested a fresh launch of Photoshop CS6 which is the largest app I run in OSX and since it never changes it's a perfect candidate, lo and behold, the app launch time was now pretty much half of what it was prior to the procedure.

In conclusion, this confirms that the Windows based tool provided by Samsung will work on mixed partitions and that it does it's magic across the entire drive, not just the Windows NTFS partition.

Thanks Samsung! I can now put the 840 EVO back in my recommendation list, although the 850 EVO will most likely replace it soon enough as far as budget "bang for buck" SSD goes.

October 24, 2014 | 05:29 PM - Posted by ablatt

Samsung released version 1.1 of the Performance Restoration Tool. They say you can't run it if you already ran version 1.0, which I had.

"If users restored performance with ''Samsung Performance Restoration v.1.0'', users do not need to use ''Samsung Performnace Restoration v.1.1''. (Tool does not work) "

I uninstalled version 1.0, installed version 1.1 and it went throught the whole restoration process, minus the firmware update portion.

I uninstalled version 1.1, reinstalled it, and it wouldn't let me run the Tool again.

From the PDF, the changes in v.1.1 are:

1. GUI (Progress bar) improved
2. Improved compatibility of detecting drives with some PC systems

Why did version 1.1 run if I had already run version 1.0? Is there any harm in it?

October 29, 2014 | 10:56 PM - Posted by Bob Roberts (not verified)

I tried this performance tool and then I get all this hoo ha about my AHCI driver. Then allllllllllll the stuff I would have to do to update the driver. I have the most recent drive installed. I don't get it. Why doesn't magician do what it is supposed to do and update the firmware so then a person can then do the performance tool. I mean are they going to incorporate this into Magician in the future or are they going to leave this like for those that have to do allll this tricky stuff with drivers and what have you that in my case are all intact and up to date. I don't feel all that confident in updating drivers when I have no clue what drivers they are really looking for. Microsoft drivers keep telling me in 8.1 its the most recent driver. Whats going on here. I'm not to happy to tell ya the truth how Samsung is not very upfront on the issue. I paid a lot of money for this thing and the least they could do is make this problem fix far easier than this. Magician should be taking care of this well first SAMSUNG really should be the one to fix Magician and create the firm ware update through that instead of all this other stuff. I'm lost quite frankly even with the stupid steps in the pdf file. HELP please.

October 31, 2014 | 12:11 AM - Posted by Oscar Castillo

Curious if anyone has updated their Mac with the ISO? Any issues?

November 1, 2014 | 04:56 PM - Posted by PIPPO (not verified)

I tried, by usb pen and by external CD and it was impossible.
The problem is the MAC's don't start with dos.

November 1, 2014 | 04:58 PM - Posted by PIPPO (not verified)

I tried, by usb pen and by external CD and it was impossible.
The problem is the MAC's don't start with dos.

November 5, 2014 | 08:57 PM - Posted by Conrad  (not verified)

Yes, I have updated my Mac with a CD burned from the ISO provided by Samsung. But for the downloaded Samsung ISO to boot a Mac from a CD, you have to change it to a DMG (renaming it is enough); at that point you can burn the image to CD from Disk Utility and it will boot and run. I documented the steps here:

As far as I can tell the Samsung USB key software seems to be impossible to use on a Mac as downloaded, because it requires a proper EFI. That means you have to assemble the bootable USB key yourself using software from multiple sources on the net, and using the Terminal is practically required. Naturally, all of that is a bit of a challenge except for advanced users. Since my Mac still has an optical drive, I decided to burn a CD-RW instead because that took 5 minutes. (You can boot an Intel Mac from DOS on a CD; that doesn't have the same EFI restriction as booting from USB keys.)

Overall the Samsung software for the Mac is too much of a challenge for less technical users because the Samsung software is incomplete (not ready-to-run as downloaded), yet the Samsung documentation, which is written for IT types, doesn't fully disclose how incomplete it is.

October 31, 2014 | 07:49 AM - Posted by Fabiano G. Souza (not verified)

I tried to use the windows program to no avail. The problem with the AMD driver was unsolvable to me. I used the DOS tool and it worked. But it has only has two steps. When i run it again, the windows tool continued to work. It blazed through steps 1 and 2 and did a long step 3.

Like someone said here, it´s absurd that the Samsung Magician did not has given any notice about the new firmware or about this very grave problem. I got to know it for mere luck listening to TWiT.

I noticed my system not so fast for SSD for some time but blamed Windows. My Steam's The Witcher 2 install is in the SSD and the load times were terrible. Inital tests showed a perceivable improvement.

Thanks for PCper for the heads up about this grievous problem.

October 31, 2014 | 03:35 PM - Posted by CT (not verified)

Thanks for sharing your findings with the Samsung Performance Restoration Tool for 840 EVO.

Have there been any tests with an 840 EVO that is encrypted with bitlocker? (Testing after unlocking, and testing with files locked)

November 5, 2014 | 08:58 PM - Posted by CC (not verified)

Yes, I have updated my Mac with a CD burned from the ISO provided by Samsung. But for the downloaded Samsung ISO to boot a Mac from a CD, you have to change it to a DMG (renaming it is enough); at that point you can burn the image to CD from Disk Utility and it will boot and run. I documented the steps here:

As far as I can tell the Samsung USB key software seems to be impossible to use on a Mac as downloaded, because it requires a proper EFI. That means you have to assemble the bootable USB key yourself using software from multiple sources on the net, and using the Terminal is practically required. Naturally, all of that is a bit of a challenge except for advanced users. Since my Mac still has an optical drive, I decided to burn a CD-RW instead because that took 5 minutes. (You can boot an Intel Mac from DOS on a CD; that doesn't have the same EFI restriction as booting from USB keys.)

Overall the Samsung software for the Mac is too much of a challenge for less technical users because the Samsung software is incomplete (not ready-to-run as downloaded), yet the Samsung documentation, which is written for IT types, doesn't fully disclose how incomplete it is.

November 18, 2014 | 03:33 PM - Posted by Grateful (not verified)

Thank you for these excellent posts. I have a Macbook Pro with a Superdrive so I was able to create a CD using the .iso file copied to a .dmg then used Disk Utility to burn. I have both OSX and Bootcamp (Win 7.1) partitions on the 840EVO 512G. Could not find any online references to anyone who had OSX and Windows on the same disk so I decided to strike out on my own.

0. Made sure my OSX volume had recently been backed up via Time Machine.
1. Downloaded the .iso file in OSX, copied to .dmg, then burned CD using Disk Utility. Thanks, Conrad, for the excellent procedure.
2. Rebooted into Bootcamp, downloaded the .zip file for Windows, extracted the contents, and ran the executable. It reboots the system once back into Windows. Firmware got updated and the NTFS partition was processed in three stages. I have about 100GB formatted as NTFS and it took less than an hour. Documentation states the Windows version will work only on NTFS, so I decided I'd better also run the bootable CD to do the HFS OSX partition.
3. Rebooted into Windows, no problems.
4. Restarted from OSX, holding down option key until presented with multiple boot disk options, selected the CD.
5. CD booted into DOS, did not update firmware, then started Stage 1 which went pretty fast. Stage 2 was chugging along then my screen went blank and nothing seemed to be happening. So I shut off the computer and restarted, holding the option key again until I could boot from the CD again. Firmware skipped, Stage 1 done fast, Stage 2 began again. I left it alone and went to bed.
6. Next morning, Stage 2 was complete, taking 4 hours and 34 minutes. Back to a DOS prompt. Wow, so 1980's. No command to reboot here (put in a ? and got a list of commands, and EXIT did nothing). Powered off.
7. Held the option key down and restarted. Selected the OSX partition and booted up. All good.

I ran no before or after benchmarks but subjectively programs seem to load a bit faster.


November 22, 2014 | 08:38 PM - Posted by Al M. (not verified)

Any idea when these drives rolling off the assembly line will have this fix already incorporated in them? I bought one for my daughter a few weeks ago, and a friend ordered one a few days ago. Is there a serial number we can go by?

December 8, 2014 | 11:51 AM - Posted by jtiger102

Allyn, is there any update on the performance of the "stale" drives that had been touched with the performance tool? I know you were holding on to for testing purposes to see if the tool did what it was supposed to do and didn't have any adverse effects that would creep back up.

December 20, 2014 | 08:35 PM - Posted by Kingkookaluke (not verified)

I' am still getting half speeds of the reads on my 840's.. anyone else? From 1100 down to 500 in raid 0.

December 20, 2014 | 08:36 PM - Posted by Kingkookaluke (not verified)

I did the updates prior to raiding the drives. FYI.

December 20, 2014 | 08:37 PM - Posted by Kingkookaluke (not verified)

This is a recent event as well guys. I don't think that the flaw is really fixed.

December 20, 2014 | 08:39 PM - Posted by Kingkookaluke (not verified)

It may be in a non-raid configuration...I'm just saying..Al help me out here please after the Holidays! and by the way.... I really want to win that car!

December 29, 2014 | 06:21 PM - Posted by Mike Klausing (not verified)

I am going to replace my CD SuperDrive with a 840 EVO drive. I have thunderbolt on my iMac. I have an Kannex Thunderbolt to USB 3 and esata connectors. Can I use the esata connector for this updating? I will power thru another source.

March 2, 2015 | 02:51 PM - Posted by Anon (not verified)

Should I run this software if I'm having no issues or wait and use it if I ever see performance drop?

April 24, 2015 | 01:16 AM - Posted by ucity (not verified)

My SSD EVO 840 500GB is having a very bad performance.
- Sequential Read: 68MB/s - max 540MB/s
- Sequential Write: 62MB/s - max 520Mb/s
- Random Read : 14973 - max 98000
- Random Write : 10862 - max 90000

I have the latest Magician software downloaded (v46)
Magician also updated the firmware to version : EXTODB6Q, which is the latest. However, the performance is still the same.
I've heard and read about Performance Restoration tool from Samsung, but could not find in Samsung download site.
Can you please let me know where I can find this software? What are the other options?

June 12, 2015 | 04:43 AM - Posted by Roy (not verified)

I had some bad luck following the suggestions ubove for updating the firmware on my RAIDed Evo 840 and feel I should write this to caution others. Take note that I did have a BSOD after I successfully de-RAIDed my 2xEvo 840s in Windows 7, but not right away - a few minutes after while on the desktop.

I have an intel comtroller with 6 ports and two RAIDs on it:

1) 2xSamsung Evo 840 256gb in RAID0
2) 4xSeagate SSHD 2tb in RAID10

I followed all the instructions but when I completed step no. 7 and re-enabled RAID in BIOS - my other 4xSeagate SSHD 2tb RAID had 'FAILED'. I am still in the stage of fixing it but I felt I had to come up here and give some warning so that other could benefit if they had this happen to them.

If this happens to you - you can still salvage your data from the 'FAILED' RAID. What I did was:

1) Most important thing is not write or initialize or do anything destructive to any of the disks from the lost array.

2) Go to intel RAID in bios and 'Reset Disks to Non-RAID' and choose all of the disks from the failed array.

3) In windows do nothing to the separate disks (if disk manager pops up telling you to initialize them or something).

4) Get an empty disk big enough to hold all your data from the array (I had to buy one 4tb disk)

5) Download "ReclaiMe Free RAID Recovery" and use it to find the original RAID configuration from the now-separate disks and rebuild it (you could use any other software if you like).

6) Write the RAID from the failed now-separate disks to the empty disk you have set up.

7) Redo the 'FAILED' RAID from scratch and put your data back on it.

I still didn't do those two last parts as I am waiting for the 4tb disk I bought to finish formatting - so I hope it actually IS free. I have used reclaiMe to see if my data was actually still there and I was very relieved to find out that it was all still there.

There are other things you could do and I have tried using testdisk to write the partition table and when that didn't fix my problem I tried copying the backup boot sector with it but my backup was bad (maybe had nothing to do with my problem as it was not used as an OS volume - but tried that anyway). When testdisk didn't fix my problem I defaulted to use the solution stated above.

I hope this helps anyone who found himself/herself in the same situation.. and good luck.

If this is a common problem when you have more than one RAID on the controller it would be a really good idea to add some warning in the article itself.

September 7, 2015 | 04:48 PM - Posted by tbworoby (not verified) it is, september 2015, and i still cannot get my DTX06B0G firmware upgraded...i have magician v.7 and still nothing...error message "firmware upgrade failed"...
c'mon guys, what is going on!...cannot get to samsung to ask why, no FAQ's on the problem (except to refer to magician, which has NEVER worked for the upgrade), my big bucks ssd has just been tested to be SLOWER than my WD platter!...and still no resolution from samsung!
i will not recommend samsung for ssd's, due to their incompetence, indifference, and aloofness (no contact info)...cannot contact them for advice, the software just does not work, and any faq's point back to the worthless magician software firmware upgrade...and for this i paid big bucks?

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