Subject: Re: ATAPI UltraDMA questions...
To: None <>
From: Wolfgang Rupprecht <>
List: netbsd-users
Date: 02/28/2001 10:45:13
> > Are there any *reliable* benchmarking tools to check
> > performance of disks too?
> dd if=/dev/rwd0d of=/dev/null ns=64k count=8192
                                bs (???)

> > I'm currently investigating these as alternatives
> > to SCSI disks as they are half the cost and they
> > are almost as fast.
> half?!  1/4 costs!!!!

I think the raw performance of IDE is quite good (especially if you
only put one disk on a cable). The IBM DTLA-307075 (an IDE drive)
reads at 36.4 MBytes/sec.

    # dd if=/dev/rwd1d of=/dev/null bs=64k count=40000
    40000+0 records in
    40000+0 records out
    2621440000 bytes transferred in 72 secs (36408888 bytes/sec)

Thats not that shabby...  

The one caveat is that all current drives are zoned, meaning that they
are faster on the outer (low-numbered) tracks than the inner ones.
The above IBM slows down by a factor of ~2 on the inner tracks.

       Wolfgang Rupprecht <>
Coming soon: GPS mapping tools for Open Systems.