The Barracuda IV listed in your 8500 setup should be faster than the
SCSI due to higher platter density (ATA one has 2 platters w/40GB each;
the SCSI drive has 11 platters with only about 4.5GB each) and a newer
drive chipset. The ATA controller is likely what's slowing down
performance.
ATA cards have had issues with the older PCI slots from the beginning
and Sonnet's seem to be some of the most consistent in that regard. The
most noticeable symptom has been stuttering when playing back audio.
From my understanding it results from some kind of improper
synchronization and the PCI bus gets overloaded. SCSI controllers have
remained devoid of this issue. I've personally never had a performance
or stuttering problem when using Acard's adapters though. YMMV.
On Jan 17, 2006, at 7:34 AM, Peter da Silva wrote:
I am honestly surprised that you get that kind of throughput on a
Powersurge motherboard through the PCI bus. The Powersurge PCI bridge
is notoriously bad, and I've seen claims that the available bandwidth
is as low as 17 MB/s. Are you sure that your measurements allow for
the disk cache?
The PCI bandwidth is actually comparable to the Beige G3. From what
I've read over time the write speeds are limited to about 40MB/s give
or take a couple MB for the PCI PowerMacs. The Beige G3 is around
45MB/s or so for writes. I've run Throughput and SCSI drive benchmarks
on both and it comes out to about that. The PCI controller chips in
older PowerMacs seem to have a much lower bandwidth on write functions,
though I don't know the exact technical details on why that is.
The read speed supposedly tops out around 125MB/s (technical limit is
133MB/s so the read functions are up to spec; a few MB is used by
normal communication overhead) but I've never had anything fast enough
yet to test it myself.
The Bandit controller is not inherently bad at all, just an older chip.
The B&W G3's 64-bit PCI slots can do faster read functions I believe,
but writes are still limited to around 53MB/s.
--
Unsupported OS X is sponsored by <http://lowendmac.com/>
Support Low End Mac <http://lowendmac.com/lists/support.html>
Unsupported OS X list info <http://lowendmac.com/lists/unsupported.html>
--> AOL users, remove "mailto:";
Send list messages to: <mailto:[email protected]>
To unsubscribe, email: <mailto:[EMAIL PROTECTED]>
For digest mode, email: <mailto:[EMAIL PROTECTED]>
Subscription questions: <mailto:[EMAIL PROTECTED]>
Archive <http://www.mail-archive.com/unsupportedosx%40mail.maclaunch.com/>
iPod Accessories for Less
at 1-800-iPOD.COM
Fast Delivery, Low Price, Good Deal
www.1800ipod.com
