On Wed, 21 Mar 2001, Greywolf wrote:
> I will beg to differ on this point.
>
> wd0 at pciide0 channel 0 drive 0: <Maxtor 51536H2>

> wd1 at pciide0 channel 0 drive 1: <WDC WD102BA>

> starjumper 501# dd if=/dev/rwd0d bs=64k count=16384 of=/dev/null
> 16384+0 records in
> 16384+0 records out
> 1073741824 bytes transferred in 32 secs (33554432 bytes/sec)
> starjumper 502# dd if=/dev/rwd1d bs=64k count=16384 of=/dev/null
> 16384+0 records in
> 16384+0 records out
> 1073741824 bytes transferred in 47 secs (22845570 bytes/sec)

Those are different drives, so you're not testing the same thing. And
note that neither of those even come close to 66MBbytes/sec, much less
100... What you want to test is the _same_ drive, running at Ultra/66
and Ultra/100. I bet if you added some flags to your wd0 config line to
limit it to Ultra/66, you'd still get ~32MBytes/sec out of it.

Maxtor claims the 51536H2 has a maximum transfer rate of 49.5MBytes/s
and WDC claims the WD102BA has a max transfer rate of 284Mbits/s, which
I'm not sure how to translate to MBytes/s, since I suspect they're
counting ECC bits and stuff. Even if we say 8 bits/byte, that works out
to 35.5MBytes/s.
-- 
Name: Dave Huang         |  Mammal, mammal / their names are called /
INet: khym@azeotrope.org |  they raise a paw / the bat, the cat /
FurryMUCK: Dahan         |  dolphin and dog / koala bear and hog -- TMBG
Dahan: Hani G Y+C 25 Y++ L+++ W- C++ T++ A+ E+ S++ V++ F- Q+++ P+ B+ PA+ PL++