In my own observation, based on mostly the lower end Samsung SSDs (840/840 evo) in desktops and laptops at home and work, the SSDs I've been using (one even failed) appear to have problems reading back 'very stale' (year or two old) data.
I've recently been backing them up, using the 'ATA security erase' (I'm doubtful this is really a security erase instead of 'factory re-trim' erase) command, and then restoring the backup. This appears to improve read performance, and I hope it also allows the drive to continue operating for it's intended lifetime.
I hypothesized this might help after observing that magnetic hard disks also exhibited a recovery of read performance after a 'non-destructive write test' using the badblocks program.
I've recently been backing them up, using the 'ATA security erase' (I'm doubtful this is really a security erase instead of 'factory re-trim' erase) command, and then restoring the backup. This appears to improve read performance, and I hope it also allows the drive to continue operating for it's intended lifetime.
I hypothesized this might help after observing that magnetic hard disks also exhibited a recovery of read performance after a 'non-destructive write test' using the badblocks program.