re: Anyone running a Samsung 840 EVO SSD should read this (new firmware released)

Here's a direct link to download the fix:

LINK

Extract and run the program. It's a "Performance Restoration" program that first installs the new firmware, reboots your PC (or in my case turned it off and I had to turn it back on myself), then rewrites every block to refresh the drive. Takes a little while to do that part if you have a lot of data.

If there's something on the drive you don't want to lose, I'd recommend doing a backup beforehand, because shite can happen. (Full disclosure: I installed the firmware and did the refresh without backing anything up, and there were no issues, but I don't always practice what I preach and nothing on my SSD is irreplaceable).


Here's Samsung's official statement on the bug:

quote:

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ecause 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.

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To summarize an article on PC Perspective, cell voltages in flash memory shift over time, and controllers are designed to correct and adjust voltage thresholds as it sees errors. The EVO wasn't doing that but instead trying to perform error correction on all data when its cells drifted far enough to the default voltage threshold.