Samsung updates 840 EVO Performance Restoration Tool

Subject: Storage | October 27, 2014 - 02:59 PM |
Tagged: Samsung, firmware, 840 evo

Over the weekend Samsung silently updated their 840 EVO Performance Restoration Tool. The incremental update improved support for some system configurations that were previously not recognizing an installed 840 EVO. Samsung also improved how the GUI progress bar responds during the update process, presumably to correct the near silent failure that occurred when the tool was unable to update the drive's firmware. Previously, the tool would halt at 15% without any clear indication that the firmware could not be updated (this would occur if the tool was unable to issue the necessary commands to the SSD, mainly due to the motherboard being in the wrong storage controller mode or using an incompatible storage driver).

DSC05837.JPG

Still no word on relief for those owners of the original 840 (non EVO or Pro). We've also heard from some users with Samsung OEM TLC-based SSDs that showed the same type of slow down (some variants of the PM851 apparently used TLC flash). More to follow there.

We evaluated the Samsung 840 EVO Performance Restoration Tool here. If you've already successfully run the 1.0 version of the tool, there is no need to re-run the 1.1 version, as it will not do anything additional to an EVO that has been updated and restored.

Source: Samsung

Podcast #322 - GTX 980 4-Way SLI, Samsung's EVO Performance Fix, Intel Earnings and more!

Subject: General Tech | October 16, 2014 - 01:16 PM |
Tagged: podcast, video, nvidia, GTX 980, sli, 3-way sli, 4-way sli, amd, R9 290X, Samsung, 840 evo, Intel, corsair, HX1000i, gigabyte, Z97X-UD5H, Lenovo, yoga 3 pro, yoga tablet 2. nexus 9, tegra k1, Denver

PC Perspective Podcast #322 - 10/16/2014

Join us this week as we discuss GTX 980 4-Way SLI, Samsung's EVO Performance Fix, Intel Earnings and more!

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The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

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Subject: Storage
Manufacturer: Samsung

Introduction

** 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.

900x900px-LL-4985de76_2014-09-1720.18.26TestresultsforC_0.png

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:

threshold shift.png

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:

840 EVO 512 test hdtach-2-.png

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!!

Podcast #320 - Micron M600 SSD, NVIDIA and Adaptive Sync, Windows 10 and more!

Subject: General Tech | October 2, 2014 - 02:05 PM |
Tagged: X99 Classified, X99, video, tlc, tegra k1, ssd, Samsung, podcast, nvidia, micron, M600, iphone 6, g-sync, freesync, evga, broadwell-u, Broadwell, arm, apple, amd, adaptive sync, a8, 840 evo, 840

PC Perspective Podcast #320 - 10/02/2014

Join us this week as we discuss the Micron M600 SSD, NVIDIA and Adaptive Sync, Windows 10 and more!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

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Hosts: Ryan Shrout, Jeremy Hellstrom, Josh Walrath, and Allyn Malventano

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Podcast #319 - GTX 980 and 970, Noctua NH-D15, Acer's 4K G-Sync Display and more!

Subject: General Tech | September 25, 2014 - 12:24 PM |
Tagged: podcast, video, GTX 980, GTX 970, maxwell, nvidia, amd, noctua, NH-D15, acer, 4k, 4k gsync, XB280HK, 840, 840 evo, Samsung

PC Perspective Podcast #319 - 09/25/2014

Join us this week as we discuss our GTX 980 and 970 Review, Noctua NH-D15, Acer's 4K G-Sync Display and more!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

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Hosts: Ryan Shrout, Jeremy Hellstrom, Josh Walrath, and Allyn Malventano

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Subject: Editorial, Storage
Manufacturer: PC Perspecitve
Tagged: tlc, Samsung, bug, 840 evo, 840

Investigating the issue

** Edit ** (24 Sep)

We have updated this story with temperature effects on the read speed of old data. Additional info on page 3.

** End edit **

** Edit 2 ** (26 Sep)

New quote from Samsung:

"We acknowledge the recent issue associated with the Samsung 840 EVO SSDs and are qualifying a firmware update to address the issue.  While this issue only affects a small subset of all 840 EVO users, we regret any inconvenience experienced by our customers.  A firmware update that resolves the issue will be available on the Samsung SSD website soon.  We appreciate our customer’s support and patience as we work diligently to resolve this issue."

** End edit 2 **

** Edit 3 **

The firmware update and performance restoration tool has been tested. Results are found here.

** End edit 3 **

Over the past week or two, there have been growing rumblings from owners of Samsung 840 and 840 EVO SSDs. A few reports scattered across internet forums gradually snowballed into lengthy threads as more and more people took a longer look at their own TLC-based Samsung SSD's performance. I've spent the past week following these threads, and the past few days evaluating this issue on the 840 and 840 EVO samples we have here at PC Perspective. This post is meant to inform you of our current 'best guess' as to just what is happening with these drives, and just what you should do about it.

The issue at hand is an apparent slow down in the reading of 'stale' data on TLC-based Samsung SSDs. Allow me to demonstrate:

840 EVO 512 test hdtach-2-.png

You might have seen what looks like similar issues before, but after much research and testing, I can say with some confidence that this is a completely different and unique issue. The old X25-M bug was the result of random writes to the drive over time, but the above result is from a drive that only ever saw a single large file write to a clean drive. The above drive was the very same 500GB 840 EVO sample used in our prior review. It did just fine in that review, and at afterwards I needed a quick temporary place to put a HDD image file and just happened to grab that EVO. The file was written to the drive in December of 2013, and if it wasn't already apparent from the above HDTach pass, it was 442GB in size. This brings on some questions:

  • If random writes (i.e. flash fragmentation) are not causing the slow down, then what is?
  • How long does it take for this slow down to manifest after a file is written?

Read on for the full scoop!

Now on Amazon: 1TB Samsung 840 EVO SSD for $399, ASUS PB287Q 4K for $649

Subject: General Tech, Displays, Storage | June 19, 2014 - 03:56 PM |
Tagged: Samsung, ssd, 840 evo, 1TB, amazon, pb287q, asus, 4k

A couple of really nice Amazon picks hit my email box today and I thought they were worth posting for our readers as well.

samsung840evo.jpg

1TB Samsung 840 EVO for $399

First, and clearly the most exciting: the 1TB version of the Samsung 840 EVO SSD is now selling for just $399. That comes in at $0.399/GB, which is actually better than the cost per GB of the Crucial MX100 that launched this month. If you haven't picked up an SSD that is big enough to hold all your games, this is the perfect opportunity!

asuspb287q.jpg

ASUS PB287Q 4K 28-in monitor for $649

Also, after our review went up at the end of May, the 4K ASUS PB287Q 28-in monitor is finally up for sale on Amazon for $649 with a shipping date of July 1st. If you think you might be interested in the universe of gaming at 4K, now is a great time to jump in.

Thanks for supporting PC Perspective!

CES 2014 Podcast Day 1 - Lenovo, NVIDIA Tegra K1 and G-SYNC

Subject: General Tech | January 6, 2014 - 04:24 AM |
Tagged: video, transporter sync, transporter, tegra k1, tegra, Samsung, podcast, nvidia, g-sync, 840 evo, 840

CES 2014 Podcast Day 1 - 01/05/14

It's time for podcast fun at CES!  Join us as we talk about the first day of the show including a lot of announcements from Lenovo, the NVIDIA Tegra K1, G-Sync and more!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

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Hosts: Ryan Shrout, Josh Walrath, Allyn Malventano and Ken Addison

Program length: 44:31

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Coverage of CES 2014 is brought to you by AMD!

PC Perspective's CES 2014 coverage is sponsored by AMD.

Follow all of our coverage of the show at http://pcper.com/ces!

Podcast #262 - Live from QuakeCon 2013!

Subject: General Tech | August 1, 2013 - 01:35 PM |
Tagged: video, shield, Samsung, quakecon, podcast, nvidia, frame rating, crossfire, amd, 840 evo, 7990

PC Perspective Podcast #262 - 08/01/2013

Join us this week as we discuss NVIDIA SHIELD, the Samsung 840 EVO, Viewer Q&A, and much more LIVE from QuakeCon 2013!

You can subscribe to us through iTunes and you can still access it directly through the RSS page HERE.

The URL for the podcast is: http://pcper.com/podcast - Share with your friends!

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Hosts: Ryan Shrout, Josh Walrath, and Allyn Malventano

Program length: 1:19:01

More on Samsung's new cached SSD wizardry

Subject: Storage | July 26, 2013 - 06:08 PM |
Tagged: TurboWrite, tlc, ssd, slc, Samsung, 840 evo, MEX controller

Along with Al's review of the new EVO line you can get a second opinion from The Tech Report about the performance of the new SSD with a fast cache.  The majority of the storage is 19nm TLC NAND but there is an SLC cache sitting between the controller and that long term TLC storage to help with the overall responsiveness of the drive, aka TurboWrite. In the 120 and 250GB models that cache is 3GB while in the larger models you get a 6GB cache.  In their real world testing the new EVO drive is incredible at large file copying though Sandforce drives can beat it in small file copy speeds, likely thanks to the compressed write trickery that controller family is so good at.  Check out the review here and keep your fingers crossed that MSRP is the acual price these drives sell at.

TR_nand.jpg

"Samsung's entry-level 840 EVO SSD combines affordable TLC NAND with a server-style SLC cache. We explain the drive's unique buffering tech and explore how it affects performance."

Here are some more Storage reviews from around the web:

Storage