Update: Samsung is readying a “Performance Restoration Tool” that will reportedly fix the problem. It will be available on their download page “on end of October”
If you have been weary of using an SSD employing 3-bit TLC flash, your circumspection may be paying off right now. Hundreds of Samsung EVO 840 series SSD users are reporting at various discussion boards that the longer data remains on the drive, the slower read speeds become. The problem is demonstrated here by Overclock.net user gino074:
It’s unusual for read speed on an SSD to be affected in this way even after heavy use, so this is either a bug in the drives themselves, or an inherent problem with the type of flash being used. For Samsung and their users, we hope it’s the former, because it can presumably be fixed. Tech Report reached out to Samsung on this issue, and they are aware of it:
Samsung recognizes the seriousness of any potential degradation of read performance on old data. We are testing and validating the circumstances that potentially cause this performance drop and will work diligently to resolve the issue.
So at the very least, they have acknowledged that there is an issue, and that it will be worked on. Let’s hope that their diligent work can fix this.