The purpose of TRIM command is to instruct block device about which data blocks are now actually free e.g. in case of file delete operation, so that SSD write operation does not degrade over time. But it requires extra erase operation every-time such event happens at file system level. Flash memory media have individually erasable segments, each of which can be put through a limited number of erase cycles before becoming unreliable. So, such SSD's will have better life but their performance would degrade over period of time.
So to avoid this write amplification problem, they came up with cache on controller solution, I think its available on Intel's SSD controllers. It helps in performance improvement as well as wear leveling. Correct me if I am wrong here. TRIM command is supported in linux kernel. http://kernelnewbies.org/Linux_2_6_28#head-a1a9591f48fe0cf8fde1f0d1f637c7ae54ad0bfa -Vinit On Sun, Sep 6, 2009 at 4:49 PM, SandeepKsinha <sandeepksi...@gmail.com>wrote: > Hi All, > > Some of the SSD's implement trim as a "no-op"? I also heard that they > have better wear life? > > Quoting from some expert's comment: > > They purposely allocate every logical block at initialization time so > the drive is > effectively "aged" from the outset. This way the performance doesn't > change over time. They implement a huge amount of back-end bandwidth to > handle the resulting write amplification. > > What exactly does this mean? > > -- > Regards, > Sandeep. > > > > > > > “To learn is to change. Education is a process that changes the learner.” > > -- > To unsubscribe from this list: send an email with > "unsubscribe kernelnewbies" to ecar...@nl.linux.org > Please read the FAQ at http://kernelnewbies.org/FAQ > >
