Early October 15, 2014, Samsung released a program that was supposed to fix the problem on the 840 EVO by updating the its firmware to version EXT0CB6Q
and then executing a one-time refresh of all data on it. However, several months later, people started noticing that the read speeds were slowing down again.
Finally, on April 23, 2015, Samsung released a new firmware version EXT0DB6Q
via Magician, and it appears to greatly improve the read speeds of old data (from <150 MB/s to >350 MB/s) while doing some sort of calibration/rewriting in the background to slowly bring the speeds of old files up to a full 500 MB/s and keep old data fresh.
For the latest firmware update, please see the Samsung SSD Downloads
page. As of this writing, the latest firmware is available via Magician, a standalone Windows updater, or a bootable updater for Mac and other users.
Recently, I came across this thread here on OCN
detailing how as data ages on the Samsung 840 EVO, the SSD's retrieval speed of those old files can drop dramatically, sometimes even to speeds below 50 MB/s on files that are a few months old!
This problem went undetected for about a year because regular SSD benchmark programs write their own test file (to test write speeds), and then immediately turn around and read that same file to test read speeds. This means that all the traditional SSD benchmarking programs never see this phenomenon because they are always reading a fresh file. Since testing for this strange SSD behavior would require a new method of benchmarking, I wrote a new benchmarking program that would specifically test for an age/speed correlation by reading files already on the SSD, and then display its findings graphically.
If you're interested in testing your SSD, you can download the latest version here: SSDReadSpeedTester2.04.zip
The first time you run SSD Read Speed Tester
, it may ask for administrative privileges to install a small runtime component (comctl32.ocx). The program itself is standalone/portable. If the component is already installed (or you manually install it yourself), the program won't ask for administrative privileges.
SSD Read Speed Tester
saves a PNG picture for upload on this thread (if you're so inclined to share your results with us), and two TSV (tab separated values) files for further analysis for those who want to have the raw data for importing into spreadsheet/graphing software. Please be advised that one of the TSV files contains the pathname of every file tested. I am only interested in the picture.
Thanks to all the OCN members who tested their SSDs with my program and shared the results, I have confirmed that this phenomenon has been found to plague the Samsung 840 EVO SSD
, and affect the Samsung 840 (non-EVO) SSD somewhat. I have collected the results in my next two posts for easy perusal.