>
> It seems Arun Sharma wrote:
> > > Do you have the prober 80pin cable ?? if so please provide a verbose boot...
> >
> > Thanks, that fixed the problem. Has anyone benchmarked the driver ? A very
> > unscientific benchmark that I ran didn't seem to produce much of a difference
> > between UDMA33 and UDMA66. In both cases, I got roughly 13 MB/s.
>
> There are almost no mesureable difference between UDMA33 and UDMA66, all
> mesurements I've done (and have read about) sees little if no difference,
> in fact some drives can be faster under UDMA33 even if they support the
> higher rate too.
>
> > # dd if=/dev/ad4s2 of=/dev/null bs=40960k count=10
> > 10+0 records in
> > 10+0 records out
> > 419430400 bytes transferred in 30.797045 secs (13619177 bytes/sec)
>
> Thats probably close to what your drive can pull of the platters...
> I get 22-23MB/sec off an IBM DPTA drive here with < 1% cpu usage,
> so the driver is not the problem..
Look at your drive specs. I have one drive (Maxtor) with specs that
say ~34MB to/from media and 66MB to/from interface (bus). Another piece of
the puzzle is the amount of drive cache buffer. Again, I've seen between
512KB and 2MB. Mileage will vary... [It's the old 'burst rate of X' where
the following 378 conditions must be met to reach the burst level...]
> I have a config with 7 disks online, giving me a raw throughput
> of ~100MB/s sustained, that is about the limit of what can be done
> over the PCI bus...
>
> -Søren
>
>
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--
Joseph Thomas E/Mail: [EMAIL PROTECTED]
Network Computing Services, Inc. [EMAIL PROTECTED]
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