According to the post, the Pro series uses a different memory technology and is not effected.

I bought a 120GB 840 (non-EVO) for an office PC and never got around to installing it. I installed it from an image when this happened to my home-use PC in March.

I haven't noticed any degradation in speed, but I don't really watch when this system boots and I run serious video on the other machine.

Thanks for the link. It appears a decent workaround is just to restore the image to rewrite the cells and establish more recent voltage levels until some fix is released,
I don't really care about wearing out the drive. Like me, I treat all this stuff as expendable these days.

Based on the HDTach measurement, I'm going to ignore the issue for a while.

Samsung acknowledged this issue last week and said a firmware fix is being developed.
http://www.anandtech.com/show/8550/samsung-acknowledges-the-ssd-840-evo-read-performance-bug-fix-is-on-the-way

Fix is coming October 15.

http://www.anandtech.com/show/8570/firmware-update-to-fix-the-samsung-ssd-840-evo-read-performance-bug-coming-on-october-15th

My 840 Evo is definitely affected by the problem.

I just got a pop-up screen from the Samsung magician (SSD) software that there is a new firmware available.

Anyone ever installed a SSD firmware? And would it be worth it? I wonder how safe that process would be for the Data on the drive. (Of course I will back up the data first)

I have the Samsung 840 Pro, it doesn't have the slowness problem mentioned here.
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VMP

I've installed firmware updates on spinning disks and optical drives. I would never do a firmware update on a disk without backing up the data. Interesting catch 22 is that backing up the data will be very slow because the drive needs a firmware update.

At work, I actually had eight of these pigs that were all full by the time the firmware update was released. A few of them took the update without destroying the data, but it's like watching popcorn pop.

Thanks for the info John Dennis,

Why did the firmware upgrade take so long? Isin't the firmware data just sent to its chip set, rather than the drive itself?


VMP

Writing the firmware to the disk only took a few seconds. Backing up the data from a sloooooowwwww drive took a long time. One unit took nine hours for 250 GB.

See this Samsung site for firmware update.

Samsung SSD 840 EVO Performance Restoration Software

Did the update a few days ago, worked great. My 840 EVOs are back to running at full speed. Samsung acknowledged the problem, said a fix would be available on October 15th and delivered on that promise. I'm a happy guy.