Proper SCSI setup/advice? (for older Mac/AMIII)

[edgarbc1]

Hey all,
Ive got PM8600 (kansas-50Mhzbus-800mhzG4upgrade) running OS9.1
and Audiomedia III with PT5.1.1 LE.
I have 3 cheetah drives, 2 drives are dedicated for audio storage only (no Operating System is there)

Ive recently purchased a PCI SCSI card so i can get marginally better
read/write times for audio playback/recording... The PM8600 has
an builtin SCSI chain running FAST SCSI-2 (max 10mbps) and the
PCI card i have is ATTO ExpressPCI PSC (single channel) which is basically
the equivalent of the SCSI 64 digi card, but only 1 channel. Its Ultra Wide
SCSI-3 (max 40 mbps)

However, my question pertains to how to best run this system.
1) Should I leave my OS on the slower PM8600 chain and the have the faster read/write
disks connected to my PCI SCSI card?

or

2) Put both the OS hard disk and the audio storage disks on the PCI
card together. I always read about the intense CPU time of some plugins
and am wondering is this is wise to keep on the same PCI scsi chain...

3) also anyone know of benchmark programs that can be used for OS9?
i want to test the speed increase of this added PCI card. Ive used Xbench
for OS X, and only marginal increases were gained under this OS.


thanks!
Edgar

(by the way im also running PT6.1.2. on OS X Jaguar, if this makes any difference
in your response- im betting that OS9 is generally faster for my older system...
Xpostfacto is used for OSX)

[qgrm]

ok mr moneybags

you honestly had performance problems running OS HD off the internal IDE controller?

(mightn't losing bandwidth to a slower SCSI PCI card counteract the supposed benefits? i may be way wrong on this, techheads be sure to set me straight)

B.

[jasona]

You may not really notice a big difference between sessions running on the Fast Narrow SCSI-2 internal host and the ATTO PSC. To avoid PCI bus problems, you have to use the ATTO at a slower speed than it's capable of (you should run it at SCSI-3, single ended, 20/40), otherwise you'll get the dreaded "PCI bus is too busy" error. You'll also have to force any differential drives - if you have some - to "single ended" mode, usually done with jumpers. The ATTO card offers a wider data path, but you should be able to run the same sessions from either the interal Fast Narrow SCSI-2 or the Wide ATTO PSC card due the the track limitation of Pro Tools LE 5.1.1 (24 tracks), and the buffering limitations placed on PCI SCSI hosts. You may see the benefits of Wide SCSI if you have a lot of dense edits in a session. One of the big benefits of Wide SCSI is the availability of larger drives at lower prices than narrow SCSI drives, and the availability of 10,000 or 15,000 RPM drives.

I'd just keep your system on the internal 4 gig narrow drive and use your WIDE SCSI drives strictly for audio. I actually have an 8600 with a G3/500 upgrade, ATTO PSC and an AMIII that I keep around as a backup machine for basic tasks. I run 2 wide drives for audio off the ATTO card and keep my OS on the internal 4 gig drive. That was my main computer prior to getting my G4. Keep this in mind, on the ATTO PSC you can only use 2 of the 3 SCSI busses at a time. Either 1 internal and 1 external, or 2 internal (You have an external wide, internal wide and internal narrow.) If you use all three SCSI busses, you'll find smoke signals rising from your ATTO card.

I'll quit rambling on. Hope this helps.

[mindnoise]

In my Years of SCSI d(r)iving I can just second jasona.

keep only drives with the same interface (fast/wide etc.) on one of connectors of your ATTO.
and leave the other drive(s) on your Apple SCSI bus and you´ll be fine.

regs

[edgarbc1]

thanks for yr posts!!

>>> ouch to the Mr Moneybags zing!
(by the way i picked up the SCSI card for only $13 at ebay!!!
Item number: 2789868644 and i got some spare SCSI wide cables from
my work...

Yes I agree keep similar drives on each chain. dont mix narrow and wide
Also ive turned throttled down the card per Digi's suggestion to 32mb
burst rates...maybe ill experiment with higher burst rates just
to see what will happen....

EBC