Samsung 840 EVO SSD is a popular Solid State Drive device, one of the most sold for a long period of time. Sadly, it’s affected by a serious performance problem. Samsung released over the time multiple firmware upgrades which address the read performance slowdown. If you haven’t done it yet, it’s time to upgrade to the latest version (at the time of the writing, EXT0DB6Q).
Even after the firmware upgrades, I noticed that my 250 GB SSD suffers from dramatic write speed slowdowns. The tests performed using Blackmagic Disk Speed Test on a Mac show that write speed decreased to 45 MB/s: worse than a traditional HDD! Read speed was instead ok after the firmware upgrades, well over 450 MB/s.
I found an effective but temporary fix to regain the lost performance:
- Fill the free space of your SSD with data. For example, duplicate some large files that you already have. It will be a quite slow process, especially towards the end.
- Delete those useless files.
- Leave the PC on for 15 minutes or more and let the SSD quietly do its garbage collection.
Then, test again the write speed of your SSD. For me, the results were impressive, with stable write speeds up to 275 MB/s.
Note that this is a temporary fix: the performance will degrade again and you will have to redo the same trick.