> Create /etc/modprobe.d/atapienable containing > > options ibata atapi_enabled=1 This one shouldn't be needed, the default is atapi enabled since 2.6.18 or so. > > Create /etc/sysconfig/mkinitrd containing > > MODULES="ahci" > > to ensure that future kernel initrds will contain the ahci module. Ah I was trying to work out why it didn't "just work" - your default initrd didn't have the AHCI driver. I thought 2.6.22 should be working! > > - "hdparm -tT /dev/sda" doesn't show much difference in performance > between compatibility and AHCI modes. Where should I expect to see a > performance difference, and are there any other settings needed to help > it along? AHCI improves performance under load - the cost to issue a command is lower than with traditional IDE interfaces for one, and if your drive has NCQ support we can give the drive multiple commands at a time, and the drive is able to fulfill them out of order according to things like head position. As the drive has a list of work to do it can do it more efficiently based on its detailed knowledge of the media.
