Samsung Has Released a Fix for the Evo 840 Slow-down Bug

It has been about 3 weeks since we first reported on the slow-down bug happening on the Samsung Evo 840 drives. Samsung was quick to react on the issues and promised a fix for today. That fix has now been released and you can apply it to your own drives.

“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.”

Samsung said the problem is unique to the 840 EVO drive and not an artefact of that drive’s TLC NAND. The older TLC-based 840 series is unaffected and so is the upcoming 850 EVO which will use the three-bit version of 3D V-NAND.

Samsung has released a tool with the very fitting name “Samsung SSD 840 EVO Performance Restoration” that can be downloaded from the official support site. Once you have downloaded and installed the tool, launch it. It will update your firmware to the new version (EXT0CB6Q) before you’ll need to reboot your system. The actual restoration begins after the reboot and will take quite some time depending on the size of your drive.

I’ve just patched my personal Samsung EVO 840 with 1TB capacity and it worked like a charm. I can also report that it works fine on a AMD based system, just for those worried about updating the firmware of the drive on a non-Intel SATA port. The patching of the drive took several hours, so be patient and don’t worry if the progress-bar doesn’t move for a while. It might be a good idea to run it over night if you have one of the big models.

Thank you Samsung for providing us with these information