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!!

Intel Pushes New SSD Toolbox, Updates 335 Series Firmware MWI Bug

Subject: Storage | November 28, 2012 - 10:32 PM |
Tagged: ssd toolbox, Intel, firmware, 335

A quick note to users of Intel SSDs - specifically for owners of the 335 Series. Intel has updated their SSD Toolbox app to v3.1.2. This app is used for various tasks on Intel SSDs, such as secure erasure, performance optimization under Windows, and TRIM through RAID-0 under Intel RST / ICH / PCH motherboard SATA controllers. This update is significant in that it can in turn update the firmware of the Intel 335 Series SSDs to correct a bug in how those drives report wear. This bug was initially discovered by Kristian Vättö, over at Anandtech.

intel 335 F9.png

If you have a newer version of the SSD Toolbox, F9 will be listed as "Total NAND Writes", and list that value in MB. The issue with the original 335 firmware was that it incorrectly calculated the wear (the Wearout Indicator - E9 above) such that it would list the drive as worn out after ~1,000 total flash cell erase cycles (i.e. 1,000 x the capacity of the SSD). The firmware update corrects this value to ~3,000 cycles, which is more appropriate for the rating of IMFT 20nm flash. Updating should be non-destructive, but you should backup just in case. The update is not urgent, in that it only corrects how the drive does the math to calculate E9. The Wearout Indicator will change to the correct value after the update, regardless of when it is applied. Additionally, if the MWI reaches 0 prematurely, it should have no impact on operation of the SSD.

Grab the update here.

OCZ Updates Vertex 4 Enthusiasts to 1.4 Release Candidate Firmware

Subject: Storage | May 7, 2012 - 10:27 AM |
Tagged: Vertex 4, sata, ocz, firmware

This morning, OCZ pushed out a new firmware, dubbed 1.4RC. This is a release candidate of the upcoming performance-boosting firmware, and is meant for "enthusiasts who like to tinker with their hardware".

DSC02737.jpg

New Performance Specs in Red:
Max Read / Write
128GB: 535MB/s - 550MB/s / 200MB/s - 420MB/s
256GB: 535MB/s - 550MB/s / 380MB/s - 465MB/s
512GB: 535MB/s - 550MB/s / 475MB/s

As a heads up for those who are feeling froggy this Monday morning and choose to update their Vertex 4 - this is a destructive update and will wipe the drive. The updater runs within a Windows session with the Vertex 4 connected as a secondary drive. While you're 'under the hood', I'd also recommend performing a secure erase with the OCZ Toolbox software after you have udpated and power cycled the SSD.

I have been able to partially confirm the performance increases, and will be reporting full results later this evening (for all three capacity points). Stay tuned!

*Note* OCZ NDA'd this update for this morning, but we have not seen where they have posted it for download from their site. We will post a link in the comments below once it has become available.

OCZ's new Sandforce SF2281 firmware update tested

Subject: Storage | November 4, 2011 - 02:36 PM |
Tagged: ocz, firmware, Sandforce SF2281

The Tech Report has been investigating the OCZ 2.15 firmware update for their Sandforce SF2281 based SSDs.  The firmware was released to fix several specific issues that users were encountering which caused BSODs or stuttering during normal usage.  The testing was a little odd for The Tech Report, they certainly didn't see any BSODs after flashing to the new firmware, however they never saw any BSODs on their drives previously.  A little investigation showed them a significant decrease in the number of people complaining about BSODs on forums which leads them to believe the firmware update is effective at what it does.  Even better, the firmware has no real negative effect on the drives performance.

TR_drives1.jpg

"SandForce SSDs have been dogged by reports of BSODs and other issues, but new firmware promises relief. We take a quick look at OCZ's recent 2.15 firmware update to see how it affects SSD performance and the BSOD bug."

Here are some more Storage reviews from around the web:

Storage

 

SandForce finally patches elusive 2200 series SSD controller bug. OCZ issues firmware, others soon to follow.

Subject: Storage | October 18, 2011 - 12:25 AM |
Tagged: ssd, sandforce, ocz, firmware, bug, BSOD

Over the past few months, we had noted a seemingly disproportionate surge of negative reports from users of SandForce-2200 based SSD's. These include OCZ's Vertex and Agility 3, Corsair's Force 3 and GT, Patriot's Pyro and Wildfire, along with many others. The complete list is available in our handy SSD Decoder.

The issue at hand was random BSOD's, with the possibility of an eventual complete failure of the SSD, rendering it unrecognizeable to the BIOS or Operating System. More details (and the fix) after the break:

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I witnessed this personally, as the SF-2281 pictured above suffered the same fate when we attempted to use it a few weeks ago.

Today (hopefully) marks the answer to everyone's prayers. SandForce issued base firmware 3.3.2 for SF-2000 series controllers.

snap-397-.png

OCZ's Toolbox software V 2.40.02 can patch OCZ's line of SF-2200 SSD's with the new fix.

The release notes follow (and seem to lack mention of the aforementioned bugfix):

OCZ Toolbox version 2.40.02
---------------------------
- Modified Identity data display
- Fixed Smart data display for power fail backup attributes
- Added BIOS update for Hybrid drive

Known Issues:
- Update Firmware feature prohibited for primary drives with 1500 & 2000 controllers
- Intel RST Driver 10.1.0.1008 prohibits SSD detection

OCZ's press tidbit for the new firmware(s):

OCZ is pleased to announce that the cause of a BSOD issue experienced by some SF-2000-based drive owners has been identified by OCZ and SandForce. A new firmware update which directly addresses this BSOD occurrence related to SF-2000 based SSDs is available here. All newly manufactured OCZ SF-2000 based SSDs will feature the new 2.15 firmware revision (which is based on SandForce firmware version 3.3.2.) We highly recommend that any customers that have experienced the BSOD issue update their firmware to 2.15.
 
We sincerely appreciate the support from our customers, and if any customers have any questions or require additional support please do not hesitate to contact a customer service representative and we will be happy to address any questions or concerns.

If you own any of the affected SSD's, I highly recommend updating as soon as possible. Until then, I also recommend you back up any data present on these drives, as the above statements confirm the presence of an issue that can potentially brick your SandForce SSD at any moment.

Remember, patch only applies to the 2200 Series controller (i.e. SandForce SSD's capable of SATA 6Gb/sec).

Intel reproduces '8MB bug', fix coming soon.

Subject: Storage | July 24, 2011 - 09:22 PM |
Tagged: ssd, Intel, firmware, 320

We've seen some recent mumblings about a corner case where inadvertent or improper power loss to an Intel 320 Series SSD would result in the drive getting stuch in an inaccessible mode where it appears as an 8MB drive. From what I've gathered, the issue seems rare and may be tied to some specific hardware configurations.

external.jpg

The SSD 320 we tested back in March (we couldn't get it to 'stick' in 8MB mode).

More after the break...