It is more complex than just adding trim support to a file system.
For example there are block sizes. We usually use 512 or 1024 byte blocks on our media, while flash media internally using 128KB and even bigger blocks. So each 512 byte block write causes an 128KB block flash erase + reflash.
Depending on the internal controllers used the effect may be lower. Also the bigger the card, the less the ageing, as the internal controller swaps blocks to prevent killing a single block e.g. root/directory head, which needs to be written hundreds of times a day, while other blocks (mbr, once written files) just got a hand full of writes.
Trim just avoids that blocks a filesystem sees as cleared, are not backupped to other blocks when cycling flash cells, which a) avoids a useless flash and b) speeds up the write process.
Speaking aboud speed, recent flash media are much faster than our hardware can handle. The speed gain is produced due the lack of seek times, as we don´t have big system files.
I am using CF Cards for years now as main drive in my main system (Pegasos2) writing around 400 MB per day (entire system update + extracting ) and did not experience a single problem with it.
In fact I avoid harddrives where possible, so I even backup my files on flash media as well as using them in portable harddrives.
Geit
