Re: [git patches] IDE update

Ondrej Zary
2005-07-05T10:02:45Z

André Tomt wrote:
> Al Boldi wrote:
>
>> Bartlomiej Zolnierkiewicz wrote: {
>>
>>>>> On 7/4/05, Al Boldi <a1426z@gawab.com> 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
root@pentium:/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
root@pentium:/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

--
Ondrej Zary