Re: Cheap Flash SATA drives

Chris Samuel <chris@csamuel.org> wrote:

Pre SATA 3.1 the TRIM command was non-queued, which means the kernel had to wait for all I/O to complete before it could issue the TRIM command and couldn't send any other commands until it completed. Bad protocol design.

http://lwn.net/Articles/347511/

Which didn't help the fact that many SSDs took/take a long time to TRIM.

This was fixed in SATA-3.1 which introduced an NCQ/DSM (queued) TRIM command.

How is the protocol handled by SSDs that attach directly to a PCI-Express interface rather than to a SATA controller? Does Linux support these yet?