SSD, AHCI, and TRIM. Thread starter RU482; Start date Dec 18, 2011; Sidebar Sidebar. AHCI is a more sophisticated way for the SATA controllers to operate. AHCI is faster than IDE. HDD's do not support or recognise TRIM. If you are having issues installing an OS onto a HDD, TRIM is not involved regardless if you are using IDE.
![Trim not supported controller free Trim not supported controller free](/uploads/1/2/5/4/125499031/449141723.jpg)
I've tried other scsi commands and they work perfectly! What am i missing?Your SSD is SATA so something has to do translation of SCSI commands for it. If you want to send raw commands you should use the set native to the device/controller unless you going to use 'ATA Command Pass-Through' - i.e. You have a SCSI device behind a SATA controller but this is not the case here.Linux's libata knows how to remap some but not all SCSI commands to ATA (see ).
According to the semantics of SCSI's UNMAP don't map well to ATA so it's unlikely that mapping will ever be implemented. However, notice that sending SCSI WRITE SAME with the unmap bit set to libata is translated to ATA TRIM so you could attempt to use that.TLDR; SCSI UNMAP is not translated by libata. If you want to be protocol agnostic and have Linux do a block layer conversion for you then send a BLKDISCARD (e.g. Via the blkdiscard utility).