On Tue, Jul 05 2005, Ondrej Zary wrote: > André Tomt wrote: > >Al Boldi wrote: > > > >>Bartlomiej Zolnierkiewicz wrote: { > >> > >>>>>On 7/4/05, Al Boldi <[EMAIL PROTECTED]> wrote: > >>>>>Hdparm -tT gives 38mb/s in 2.4.31 > >>>>>Cat /dev/hda > /dev/null gives 2% user 33% sys 65% idle > >>>>> > >>>>>Hdparm -tT gives 28mb/s in 2.6.12 > >>>>>Cat /dev/hda > /dev/null gives 2% user 25% sys 0% idle 73% IOWAIT > > > > > >The "hdparm doesn't get as high scores as in 2.4" is a old discussed to > >death "problem" on LKML. So far nobody has been able to show it affects > >anything but that pretty useless quasi-benchmark. > > > > No, it's not a problem with hdparm. hdparm only shows that there is > _really_ a problem: > > 2.6.12 > [EMAIL PROTECTED]:/home/rainbow# time dd if=/dev/hda of=/dev/null bs=512 > count=1048576 > 1048576+0 records in > 1048576+0 records out > > real 0m32.339s > user 0m1.500s > sys 0m14.560s > > 2.4.26 > [EMAIL PROTECTED]:/home/rainbow# time dd if=/dev/hda of=/dev/null bs=512 > count=1048576 > 1048576+0 records in > 1048576+0 records out > > real 0m23.858s > user 0m1.750s > sys 0m15.180s
Perhaps some read-ahead bug. What happens if you use bs=128k for instance? -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html