View Full Version : Samsung Evo 840 are having read issues

Drunken Savior
09-19-2014, 11:08 AM
So this is starting to make some major waves in the tech community, mostly because of how popular the Samsung 840 Evo SSDs are. The problem lies with read speeds of older (a few months) data. People are reporting that older data is reading at speeds of around 50Mb/s. To test this, people found low read speeds on a Windows installation and then found that their speeds were as expected of a new SSD when a fresh install (i.e. new data) is made.

Here is the thread over at Overclock.net. (http://www.overclock.net/t/1507897/samsung-840-evo-read-speed-drops-on-old-written-data-in-the-drive)

I usually recommend this drive to people who want a good SSD due to the reputation Samsung has and the price point of the 840 Evo. But until Samsung fixes this problem (and many think that a firmware update to the controller can do it), I can not recommend this SSD.

For now, I'm going with my previous runner-up SSD, the Intel 530 series.

09-19-2014, 03:41 PM
whew, glad I kept delaying to buy one.

Drunken Savior
09-19-2014, 09:05 PM
As of now, the 'bandaid' solution is to...defrag your SSD. That's right. The technique used to speed up a mechanical hard drive is recommended for 'speeding up' the older data on this SSD. Weird.

Still no official word from Samsung.

Drunken Savior
09-19-2014, 09:37 PM
Still no official word from Samsung.

Nevermind. I was wrong. Found their response!

Samsung Acknowledges the SSD 840 EVO Read Performance Bug - Fix Is on the Way
by Kristian Vättö on September 19, 2014 3:23 PM EST

During the last couple of weeks, numerous reports of Samsung SSD 840 and 840 EVO having low read performance have surfaced around the Internet. The most extensive one is probably a forum thread over at Overclock.net, which was started about month ago and currently has over 600 replies. For those who are not aware of the issue, there is a bug in the 840 EVO that causes the read performance of old blocks of data to drop dramatically like the HD Tach graph below illustrates. The odd part is that the bug only seems to affect LBAs that have old data (>1 month) associated with them because freshly written data will read at full speed, which also explains why the issue was not discovered until now.

I just got off the phone with Samsung and the good news is that they are aware of the problem and have presumably found the source of it. The engineers are now working on an updated firmware to fix the bug and as soon as the fix has been validated, the new firmware will be distributed to end-users. Unfortunately there is no ETA for the fix, but obviously it is in Samsung's best interest to provide it as soon as possible.

I do not have any further details about the nature of the bug at this point, but we will be getting more details early next week, so stay tuned. It is a good sign that Samsung acknowledges the bug and that a fix is in the works, but for now I would advise against buying the 840 EVO until there is a resolution for the issue.

Hopefully we'll see a fix soon. And hopefully that fix isn't a 'bandaid' fix like having Samsung Magician (the software that manages your SSD) just rewriting older files constantly to avoid the problem, rather than addressing it directly, since we know that SSDs do have a limited (albeit a very very high limit) number of writes.

09-20-2014, 03:32 PM
Thought about buying this because my Crucial c300 SSD kept freezing the PC and dissapearing in BIOS all the time.

But I found out it was related to Intel's Rapid Storage driver. Specifically with the LPM , and you could either disable it in the registry or using Microsoft's drivers instead.

Drunken Savior
09-26-2014, 10:30 PM
Alright, Samsung has been working on a fix and it's due in just about 3 weeks.

Firmware Update to Fix the Samsung SSD 840 EVO Read Performance Bug Coming on October 15th
by Kristian Vättö on September 26, 2014 5:10 PM EST

A week ago Samsung acknowledged the existence of the read performance bug in the SSD 840 EVO and I just received a note that the fixed firmware is in validation process and is expected to be released to the public on October 15th. Unfortunately I don't have any further details about the bug or the fix at this point, or whether the update is coming to the 'vanilla' SSD 840 and OEM models, but I hope to get more details as the public release gets closer, so stay tuned.

09-26-2014, 10:41 PM
I wonder if the ones in stores will get pulled so they can apply the firmware update. I want to buy one, but I will wait till everything is out

Drunken Savior
09-26-2014, 11:10 PM
Probably not. But you're supposed to download Samsung Magician (http://www.samsung.com/global/business/semiconductor/samsungssd/downloads.html) which is their SSD tool to run your drive with anyways. In addition to basic S.M.A.R.T. health checks and driver updating, it also checks to make sure your system is optimized (AHCI, SATA III interface, and Windows Power settings) to get the maximum speed, health and/or reliability from your drive.

09-29-2014, 09:28 PM
keeping it old school with my RAID 0

if it aint broke don't fix it...my pc still plays all my games fine, boots fast, and load times are pretty fast in my eyes so I can't justify spending the money. Having said that, if my current hard drive(s) fail, I would have to go solid state.

Drunken Savior
10-16-2014, 10:42 AM
The firmware update has been released and you can download it here: http://www.samsung.com/global/business/semiconductor/samsungssd/downloads/Samsung_SSD840EVO_Performance_Restoration.zip


You'll install the firmware and then restart your PC. Upon entering Windows, the firmware update program will run and refresh (not format) your SSD. After it finishes you'll restart again and be good to go. Took me about 1 hour to do. My SSD was having the problems of hitting low, 50-200MB/s read speeds on older data. Did a quick check right after and was pleased.


Of course, the REAL test will be in about a month's time. Those speeds should still be constant. Windows DID feel snappier starting up and opening older programs after the update.

10-17-2014, 05:26 AM
nice, I just picked upa 250gb evo. so hopefully all goes good after I update it.

10-20-2014, 07:25 AM
ugh that was annoying, put in the SSD and it wouldn't get a drive, took me a while to realize to assign it a drive letter and reformat it afterwards. Now it finally works.

Drunken Savior
10-20-2014, 11:07 AM
Man, I have SO many people asking me why their new HDD/SSDs don't work. I should write a tutorial on how to use the drive manager to assign letters and format...

It'd be fucking NICE if Windows 7 (maybe they do this in 8, I donno) gave you SOME kind of popup notification that the drive needs to be assigned a letter or formatted to be recognized instead of just, well, nothing. It shows up in drive manager, but 95% of you don't even know where the fuck drive manager is.

Protip: It's in Control Panel>Administrative Tools>Computer Management>Storage>Disk Management.

10-20-2014, 01:28 PM
Yeah, if only it always was that easy. :sweat:

10-20-2014, 07:39 PM
Yah no kidding, I haven't added a new HDD/SDD to windows 7 since I got W7 and it just worked with Windows XP, any HDD that I added was automatically given a drive letter. SO here I am thinking something is wrong, so I decide to go into disk management after a hour of going into the bios, restarting the computer, safemode it, blah blah blah and I go, DOH! It needs a letter and it works now hah