Advice requested (upgrades on my G5)

Hey forum--ok, so my beloved G5 is getting a bit more of a facelift. One of the drives from my RAID (a pair of 80gb) is officially dead, and SATA drives under 500gb are super cheap, so I've decided to do a bulk upgrade right now. Here is what I'm planning:

Replace both 80gb with 250gb for a 500gb RAID
Replace my 160gb system drive with a 1TB
Use the 500gb storage drive as either a mirror for the RAID or for Time Machine (or use an external and use this for scratch or system--see below)
Upgrade RAM to 6gb (from 4.5)
Upgrade to Leopard
Upgrade to CS3

So here's my question--currently my configuration has a 160gb system drive, a 500gb storage drive, and a 160gb RAID that is used for a CS2/Final Cut scratch disc. So my main question is this: will CS3 actually run faster if the system and apps are on the RAID and the scratch is a standard SATA disc, or is it better to keep the configuration as is (i.e., use the RAID for scratch)? I know boot times will be faster of course, but even with Time Machine I worry about running the system on a RAID (I always store everything on separate drives, so all my system drive/desktop has is current files I'm working with). Basically, if the performance increase is worth the possible hassle of having to occasionally rebuild/restore, or if the RAID will actually outperform as a cache disc than a system disc...

FIREFLY--Hmmm, well I've definitely noticed a slowdown in Photoshop and Illustrator (and, oddly enough, InDesign, which is weird since indd doesn't allow you to delegate scratch discs) since the RAID died. That's part of the want for the RAM upgrade; 8 would be doable, but the thing is I bought it with 2.5 and the configuration was 4X512 and 2X256, so if I go to 6 I only need to buy 2 sticks, if I go to 8 I need to buy 6 sticks. Which is a difference of about $150; laughable when you compare that to a year ago, for sure, but the whole point is to give it a little boost for Leopard/CS3. Though I did just discuss with my business partner skipping CS3, since Adobe is already making announcements and beta runs on CS4 ware...

And yes, I work in very large files. I usually end up with pageouts, but not an insane amount (the jump from 2.5-->4.5 made a huge difference). More RAM will always help, but as of CS2 (especially on g4-bit configurations), it's still going to write a lot to cache unless you set the saved stages setting to zero (this article covers the resource hog that is Photoshop CS2: http://kb.adobe.com/selfservice/viewContent.do?externalId=320005 ).

The drives are definitely going to happen (since they can just be swapped into my next tower), it's just a matter of how they end up being configured. I might try doing a system RAID with regular time machine back-ups, see how that goes. If the drives are all the same size, then swapping between them if I change my mind shouldn't take more than opening CCC.

I think CS3 runs fine in Leopard but sluggish in Tiger; that's what I heard. I also heard that it's an improvement over CS2 in PPCs, but a much larger (dropping Rosetta needs) in Intels.

LORD ZEDD--is that confirmed? I've been holding off on Leopard mostly because of that, and that I'm not afraid of legacy OSes (we run everything from OS9-Tiger around this office, with everything but 10.0/10.1 in use). I was afraid it would actually slow performance on the G5 as I'd heard it did with the G4s my friends have tested it on...

Lord Zedd said:

Yes. The speed difference is very small, not really noticeable in daily use.

Tiger is slightly quicker but Leopard is a much better all-around system.

Click to expand...

Hrm, I may skip the Leopard bit, then, or do this in stages, as I'm already having moments of lag in extreme load, I don't need the OS contributing to it. I know Leopard is better on the consumer user-end, but my machine already does everything I need it to and is wicked stable, so until I need Leopard to run apps that I use, I'll probably stay away from it. Thanks for that!

So last call then on the last remaining question--better to run the OS on the RAID and use a standard drive for scratch or to run the OS on the standard drive and use the RAID for scratch?

That's an option too, but the question is whether or not that will actually benefit the speed of Photoshop over either of the other two options. When writing scratch cache to a drive, the heads of the drive have to work double time to run other operations AND write the cache info. That's why you should usually have your cache be a separate drive for apps, and not the same drive or a separate partition on the same drive as the OS (some riskier folks than I have even altered their systems to have the system cache write to another drive, but I'm not ballsy enough for that). I think that either of the above will result in better overall performance, but I'm not sure...

Um, no, all RAID0, I'm out for performance, not redundancy. RAID1 arrays will slow things down, not speed them up. Besides, I have a back-up system that is more efficient than time machine already.

Yeah, the thought occurred to me to max the RAM and stay smaller with the RAID and just use a RAMdisc for the primary scratch, which would work in CS2 since AFAIK it can't address more than 4gb at a time (though it wouldn't really prepare me for upgrading to CS3 or CS4, which can apparently use as much as it wants). I'll figure it all out next week, so anyone who has anymore tips please do contribute, and many thanks to all of you for your input, it is greatly appreciated.