These are some of the most popular SSDs sold in the last couple of years.
"Samsung has issued a firmware fix for a bug on its popular 840 EVO triple-level cell SSD. The bug apparently slows read performance tremendously for any data more than a month old that has not been moved around on the NAND. Samsung said in a statement that the read problems occurred on its 2.5-in 840 EVO SSDs and 840 EVO mSATA drives because of an error in the flash management software algorithm. Some users on technical blog sites, such as Overclock.net, say the problem extends beyond the EVO line. They also questioned whether the firmware upgrade was a true fix or if it just covers up the bug by moving data around the SSD."