Hi Joel, thanks for the reply. No, I'm not talking about a worn out SSD. A worn out SSD is no longer writeable. I have read the link you posted, but that doesn't answer my question. I'm referring to the erasing of previously written blocks. I had hoped that this was becoming common knowledge by now, but there seems to be a lot of confusion about it, and I think SSD manufacturers are exploiting this fact.
To put it briefly, flash memory can be written to quickly if it has never been used. If it has been used, then subsequent writes must first erase before writing. The erase process takes much longer and therefore degrades write performance. As a result of this some manufacturers have released programs such as "wiper.exe" (Google this for more explanation; there are also some long articles on Anandtech explaining SSD performance issues in detail) to allow users to periodically clear previously written flash memory, returning it to "unused" state, and restoring almost full performance. Therefore, any writes will not need to do an erase first. Unfortunately, smaller manufacturers don't provide any utilities for users to do this, so third party solutions are necessary.
Somebody on another forum told me that Eraser could be used for this, and if so, it could be added to the feature list of this software. I got the info from this post:
http://forum.thinkpads.com/viewtopic.php?p=535707#p535707