> How did you perform these benchmarks? I find it hard to believe that any
> form of IDE would outperform an NCR SCSI controller given drives of
> comparable quality. The standard CPU-usage utilities such as ps and top
> are not reliable indicators in cases such as this, because they only
> measure CPU usage in the computational sense, not bus related performance
> issues.
what i do is use the time command to time dd reads of the disks:
[root@lothar bin]# time dd if=/dev/hda of=/dev/null bs=1024k count=30
30+0 records in
30+0 records out
0.01user 1.23system 0:05.03elapsed 24%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (83major+268minor)pagefaults 0swaps
[root@lothar bin]# time dd if=/dev/sda of=/dev/null bs=1024k count=30
30+0 records in
30+0 records out
0.01user 1.27system 0:05.00elapsed 25%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (83major+268minor)pagefaults 0swaps
so it's pretty even. both cases range from 22%--26% in multiple runs.
my slowest EIDE drive only uses ~15% CPU in this test. OTOH, SCSI does
more than just busmastering which won't really show up here. still,
the only way i know which drive i'm using is by which LED is blinking.
given comparable drives, there's not a whole lot of perceptible
difference between EIDE and SCSI as long as they're both using DMA.
> > insufficient cooling. i like IBM drives a lot, but they're harder to
> > find and tend to cost a little more. i kinda worry sometimes that
>
> I don't actually have any IBM drives, but it seems that they are about the
> best quality you can get. Some of them seem to have some funny loadouts
> of cache though...
i have an ultrastar 2.1 GB SCSI drive at work which works very well. a
couple of other people in the dept have deskstars now that fry's is
relatively nearby and carries IBMs for reasonable prices. very quick
and so far reliable. too bad i don't have room at home for any more
drives else i'd get one, too.
tim
--
Time is like fingers A | Tim Pickering ([EMAIL PROTECTED])
Gesturing for me to stop -- Quake | UA Steward Observatory
Why is the sun up? Haiku | Tucson, AZ 85721 520-621-6523
--
PLEASE read the Red Hat FAQ, Tips, Errata and the MAILING LIST ARCHIVES!
http://www.redhat.com/RedHat-FAQ /RedHat-Errata /RedHat-Tips /mailing-lists
To unsubscribe: mail [EMAIL PROTECTED] with
"unsubscribe" as the Subject.
