On Mon, 2007-01-15 at 22:50 +0900, Tejun Heo wrote: > kenneth johansson wrote: > > On Mon, 2007-01-15 at 18:13 +0900, Tejun Heo wrote: > >> kenneth johansson wrote: > >>> I changed my bios setting for SATA from IDE to AHCI. > >>> > >>> This resulted in some "interesting" read throughput. > >>> > >>> plots can be found at http://kenjo.org/~ken/sata/ > >>> The plots was done on a live disk so some noise is expected but in the > >>> ahci mode the throughput get stuck at 17 MB way to much. > >> It's probably not an ahci problem but more of NCQ implementation problem > >> in the drive firmware. Please report the result of 'hdparm -I /dev/sdX' > >> and try adjust queue depth and see what happens. > >> > >> http://linux-ata.org/faq.html > >> > > > > It was, when I turn of NCQ with "echo 1 > >> /sys/block/sda/device/queue_depth" I get the same performance as when > > the BIOS is set to IDE. > > Can you play with queue depth a bit? e.g. Benchmark queue depth of 4, 8 > and 16. I did some more test "http://kenjo.org/~ken/sata/"; and queue 1 and maybe 2 works but everything larger than that has problems. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
