On Thu, Mar 06, 2008 at 01:25:06PM +0900, Tejun Heo wrote: > Denys Dmytriyenko wrote: > > > > Turning off NCQ does not help. I am currently on 2.6.23.9, but I just tried > > 2.6.25-rc4 and it is the same. > > > >>> A similar drive in an ICH7 box shows more consistent results: > >>> > >>> # hdparm -t /dev/sda > >>> > >>> /dev/sda: > >>> Timing buffered disk reads: 182 MB in 3.01 seconds = 60.48 MB/sec > >>> > >>> # dd if=/dev/zero of=file bs=100M count=100 > >>> 100+0 records in > >>> 100+0 records out > >>> 10485760000 bytes (10 GB) copied, 242.908 s, 43.2 MB/s > >>> > >>> # dd if=file of=/dev/null bs=100M count=100 > >>> 100+0 records in > >>> 100+0 records out > >>> 10485760000 bytes (10 GB) copied, 211.132 s, 49.7 MB/s > >> Hmmm... indeed. Same kernel version? Can you post "hdparm -I" results > >> of both drives? > > > > The kernel on the second box is also 2.6.23.9. Here are hdparm results for > > identical drives: > > > > 1. Connected to SiI 3124/sata_sil24 w/ slow write: > > > > # hdparm -I /dev/sda > > > > /dev/sda: > > > > ATA device, with non-removable media > > Model Number: WDC WD1600JS-75NCB1 > > Serial Number: WD-WCANM1344866 > > Firmware Revision: 10.02E01 > > > > # hdparm -I /dev/sda > > > > /dev/sda: > > > > ATA device, with non-removable media > > Model Number: WDC WD1600JS-75NCB1 > > Serial Number: WD-WCANM1356774 > > Firmware Revision: 10.02E01 > > > > Also, few months ago instead of sata_sil24 I had my drives connected to > > sata_mv (Supermicro 8-port) and performance was normal... > > Everything seems okay. I wonder where the difference is. Does "dd > if=/dev/zero of=file oflags=direct bs=1M" make any difference? And can > you vacate a raw partition and try it on there? oflag=direct has no effect - same speed. Tried it on a raw /dev/sda device and still no difference. It maybe slighly better, giving me 18 MB/s. Can it be something with the way SiI 3124 controller is configured in the system? Regards, Denys -- 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
