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Samsung 840 EVO speed slower for older data - fix released

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Samsung 840 EVO speed slower for older data

 

 

After reading about this for the past week, I already had a feeling that my EVO SDDs were running a bit slower than normal.

 

I have two 512GB 840 PRO in RAID-0 on 6Gbps Intel controllers, then two 1TB 840 EVOs running as standard on ASMedia controllers and max out at 400MB/s.

 

This initial (quickly-typed) post will be brief in this early findings and can confirm that only early 840 EVOs were not affected but mine (purchased approx 6 months ago) are affected as demonstrated below from this sequential read-test.

 

yOE4frs.png

 

840PRO RAID0 (no speed drops)

 

RFSr1qA.png

 

840EVO (older data speed drops)

 

 

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 customers’ support and patience as we work diligently to resolve this issue.”

 

The procedure for this is a pain and has to be done as the only other drive in the system, should think that the normal boot drive will be fine but need to verify this myself. No data would be affected other than re-written/re-allocated, TLC cells would be volt-corrected (it done the same cells too many times) to keep performance consistent to avoid this drop in speed over time. For this it is VITAL you back up for data and image it (I use Acronis) to a spare drive or buy a decent/cheap-ish 1TB drive to keep. This is important as the drives data could be wiped if procedure wasn't followed exactly. Remember this is a new firmware but no data is changed, only the data on the cells is moved and future performance improved through voltage correction and new algorithm in this fix.

 

Nothing is know either if over time your data my become inaccessible forever and for this reason come many months down the line, your backup will save a lot of stress. Of course it should be updated every month too at the least to have the latest image. If your data is critical I know from this being unique to Samsung SSDs that the other manufacturers aren't affected and you could just image data across to a new SSD and be up and running without any worries, totally up to you. Note: It can take several weeks for speeds to start to return to normal.

 

There is already a helpful post to fixing this issue from PCPer and you should check that out - Samsung 840 EVO Performance Restoration Tool preview.

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Yes, it shouldn't dip as low throughout sequential to 25MB/s, you should see a nice line at the top (check the 840PRO graph), also your average read speeds is low for an SSD.

 

You can also use AS SSD benchmark to see the read/write compression, HD Tune Pro for IOPS/access times/read speed, CrystalDiskMark for overview of read/write. I know there is an issue with the EVO and won't punish it even more when I simply needed to run HD Tach to check for this issue.

 

I know on my ASMedia port it can and has done 380MB/s ~ 400MB/s and now only seeing average of 216MB/s on the newer data. At the start that is old data which is the issue to start with and new firmware corrects this. I should also state that once you update the firmware, it can take weeks for the speeds to return to spec.

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I need to ask you, Mr Moderator, given that the striped 840 pros is your system drive, what is the uppermost shadowplay recording resolution you can use on your striped 840 Pros without a trace of stutter and lag appearing in the finished recording?

 

I have neither SSDs nor a card with shadowplay, but after almost six years I'm prospecting for parts to build a new PC.

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I restored the speed with Samsung tool. Took 40 minutes.

 

rH85WK0.png

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I need to ask you, Mr Moderator, given that the striped 840 pros is your system drive, what is the uppermost shadowplay recording resolution you can use on your striped 840 Pros without a trace of stutter and lag appearing in the finished recording?

 

I have neither SSDs nor a card with shadowplay, but after almost six years I'm prospecting for parts to build a new PC.

 

I don't use SSD for recording and never suffered from using a mechanical Western Digital Caviar Black 2TB HDD - my 840 PRO's are only used for OS and essential apps and all games are on the EVO's apart from Skyrim. Normally you would go for two of those drives in 4TB capacities and RAID configure them, that's what they are designed for (previous CB weren't as the firmware algorithm has been changed, much like WD did with the Red's earlier).

 

SSDs for recording isn't needed, you'll manage very easily with most 7200 RPM HHDs and compared to SSDs, not run the risk of running out of write cycles of the NAND due to huge amount of data you may end up using. IF you are editing for a living then the enterprise options like the PCI-E V-NAND cards with far superior reliability and read/write/IOPS would be on your wishlist, totally unaffordable for personal use but this is the best performance to-date.

 

Using NAND for casual gameplay recording/streaming is overkill and not necessary, only for FCAT systems is this a real requirement to capture uncompressed footage without framelimits. Applications like ShadowPlay on highest encoder preset limits recording to 50Mb/s @1080p, up to 160Mb/s @UHD and both caps framerates to 60fps. As you can see, for 4k this is very easy for 2x 4TB WD CB RAID0. The WD CB are pro-sumer/enterprise drives and come with 5-year warranty and are the drives me and some well known casters use including TotalBiscuit who just typically use one 4TB WD HDD for recordings and one SSD for game installs. Never use less than a 7200RPM HDD with 64MB cache and ensure you check the drive model thoroughly if you buy something else (you get what you pay for), they are all made with an intended use in mind so features with powersaving features or NAS drives with error correction disabled to avoid array rebuild aren't the right choices. Then all you need to do is record footage to empty array to ensure no fragmentation and archive to 1 gigabit NAS to keep the drive clean for daily use.

Edit: Got my order in this morning for a couple 1TB HDD to make images of the SSD before I start flashing the new firmware on my EVO's, delivery should be here tomorrow.

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A few days ago (after imaging my SSD to a new HDD) I completed the procedure for updating the firmware as outlined above, took 90-120mins for 500GB of data on my gaming 1TB EVO.

 

Back to normal, consistent speeds are back for Sequential/Average read. Didn't take a screenshot but there is a strong straight line as opposed to WhyCry's dips. I'd suggest you retake them with all apps closed on fresh system boot (wait 5-10 minutes) and do both a 8mb and 32mb test to see if issue is resolved. As I noted earlier, it can take weeks to settle down.

 

Had been reading that other TLC SSDs are affected, including the 845DC. OCN users reported issues with even the 840 PRO suffering performance loss but has been dismissed by Samsung despite the screenshots.

Lastly, I'd recommend you check your SMART log (via Crystal Disk Info x64) and take a screenshot of those values. Some noticed after time (yes even after this fix) values shows hints at cell degradation with high errors and went into red. Please make an image of your data, and should things go badly, you'll have something to tide you over during RMA period (3 years for EVO's and 5 for Pro - 10 for new 850 PRO).

 

Coming from my first SSD being the useless (died in 2 years) OCZ Vertex 2e 120GB *cough SATA II*, at least our SSDs work once you kick it in the balls :P

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Unlike you, I didn't care about making a backup of my disc. All important data was already on different drive, so the worst case scenario was to reinstall the system.

I'm satisfied with my drive. The issue remained unnoticed by me until I read the post at pcper.

I will possibly buy another EVO drive for RAID0 some day, but it's not the priority for me.

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A follow up by Tech Report has revealed all is not well for 840 EVOs with some SSDs showing slowdowns despite the firmware fix.
 
Note mine were on the latest ie second flash and since both use the same firmware revision you can't use it again regardless. Despite that 'fix' speeds are way down and perhaps temperamental NAND, my EVOs are showing good speeds but they were purchased in later batches. This is the line at the top showing max speeds on ASMedia controller again, no slowdown on older data as that is what you need to be aware of....

s7u3oHJ.png
 
If we had been affected again I'd contact Samsung for an explanation and ask for another firmware or failing that ask for factory sealed SSDs. Easy for people to say just buy a 850 EVO (ideally 850 PRO for reliable MLC vs EVOs TLC as on the 840 EVOs)  when you already paid hundreds for 840 EVO, why bother when the issue could show up and trust them once again. Another "if" but... if all Samsung are going to be bothered doing is release a quick firmware and say if that doesn't work you're on your own then we know what to do in future, plenty of competition and very good alternatives. Would have also liked to have tested my 840 PROs but they are in RAID 0 and would take too much time to sort out, in RAID 0 as they are no issues.

Source http://techreport.com/review/27727/some-840-evos-still-vulnerable-to-read-speed-slowdowns

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On the 28th PCPer followed up with this article, will be tracking this as a user of EVOs myself and let fellow owners know where they stand.

 

Maybe the reason I'm not seeing slowdowns yet is because both myself and WhyCry flashed back in October 2014 and usage not being regular to cause cells to slowdown. Not yet anyway. If both of us report slowdowns you can get an idea that most 840 EVO's are affected (we were originally as were others), yeah and ignoring stupid logic of sample size of 3 and all that just go with the flow  :P

 

Conclusion

After looking into this potential slow down issue, we are left with more questions than answers. Some SSDs appear to have returned to full speed and stayed there regardless of how long stale data was present. Others appear to be slowing down over time, but not as severely as they were prior to updating. The ‘cold storage’ files saved to four samples all slowed to the same ~200-250 MB/sec and could not be coaxed into recovery by any other means than overwriting them, which conflicts with a working theory of active OS drives auto-refreshing stale data in the background. We naturally reached out to Samsung for a statement, and at present we are once again at stage 1 (‘We are looking into it’). If you are affected by this slowdown again, I can only suggest you sit tight for a few weeks until more information comes about. As always, we will keep you posted as developments continue.

Source PCPer - Samsung 840 EVO Performance Restoring Firmware Only Partially Effective

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A few days ago PCper looked at the 840 EVO performance again and despite the firmware fix, issue with performance came back. They update us by saying that Samsung will release a new firmware via their Magician utility sometime next month. Difference being this time that it will be more convenient to run through Samsung Magician than using the separate performance restoration tool.

Samsung Magician 4.6 and 840 EVO EXT0DB6Q Firmware Review - Finally Fixed


Meanwhile I do have three options for those wanting a solution either now before the fix or if this ends up being the final offer then Samsung will try to ignore the issue entirely, maybe.

  1. Less drastic/time-consuming option is to open Magician and run Performance Optimisation, one down from Performance Benchmark on the left pane. Run this, takes 5 seconds, and test again. If performance from TRIM and garbage collection didn't work right away wait til the next day (important to make sure you include a couple hours of idle time = DO NOTHING) and see if it starts to pick up speed. Best to take grabs to note before/after performance for comparisons on the next step to take.


     
  2. Clone your SSD to a spare HDD and keep this as your backup. I can thoroughly recommend Acronis True Image as can my fellow technicians. Has an automated mode as well as manual. Keep the clone as 1:1 and ensure the clone to HDD doesn't increase/decrease the partition size when the same or larger than the SSD. Take care you know which is source and destination!
     
  3. DiskFresh is the one you should go for. Left this running overnight yesterday on my deteriorating first 1TB 840 EVO, second remains unaffected just yet because I didn't flash that with second firmware until 2 month afterwards.

    End story is that this works! Only affect this will have is that has to rewrite all your drives data in refreshing old data at the start of the drive, and the main cause of the slowdown. This only affects the NAND cell total write cycles and usually you get 1,000 for the lifespan of the SSD. Gamers and general usage never uses this much and even even if you went crazy you could get 15-20 years use from it, more if NVME from Intel since this is enterprise grade for 3 drive writes per day for servers, databases, editing rig, etc.



    So after that 7 hours has passed from running it overnight what are the results? Note that AS Media controller is limited to 300MB/s and why I use Samsung Rapid to push the burst/read/write speeds with an extra 2GB RAM I have spare. Once you see a straight line along the top for 300MB/s in this case you know you've fixed this issue for a while.

    Before; running DiskFresh I was tested and noted speeds down to 190MB/s and the test itself took 3 minutes longer than normal to complete


    Afterwards; this is ideal performance and running the test took the normal amount of time

If you do like these tips and share them, I would appreciate a mention in your post for the time taken and a link back to this post. Thanks! Any questions about this post just ask :) 

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Wow great work.

My EVO is affected. When I was installing GTA, my system would freeze and it behave worse than 15y old HDD. As it turned out, it had a speed of 33 MB/s (judging from Magican performance test). What I did to restore the speed was changing the profile from 'reliable' to 'performance', and like you mentioned 'perfomrnace optimization'. That did the trick. 

If I encounter any slowdowns I will try your tool to recalibrate/refresh the data on the whole disc.

I need this new firmware soon.

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Okay, I flashed the update and installed Magican 4.6, here is the result

Looks fine for now.

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