How do I use WD Raptor for OS/Apps drive and RAID 0 for Home/Data drive

Question

So far I have configured my machine with a WD Raptor 74GB as the startup disk, and created a RAID 0 with the Seagate 250 GB drive (shipped with the machine) and a 250GB partion of a WDC 320GB drive. All drives were zeroed and I used the install disks to load Tiger on the Raptor. I backed up to a LaCie D2 1TB external hard drive with LaCie's Silverkeeeper.
I would like to use the WD Raptor as startup/apps/scratch disk and the RAID 0 for the user folders and other data. I would then like to create a RAID 1 with the RAID 0 and a 500GB partion of the LaCie 1TB external.
I have learned however that what I would like and what I can have are not always compatible.
My questions:
Is the Silverkeeper backup sufficent, or should I have cloned my previous system?
What folders should accompany the application folder on the Raptor? So far I have only put the app folder there and nothing works. I suspect things like 'application support' should be there as well.
Is there a way to keep my home folder on the RAID 0 without using Terminal or spending too much time as the root user? I tried copying my home folder onto to the RAID 0 and putting an alias in the user account I had to create while installing the OS on the Raptor. This kind of works but is not a particularly elegant solution.
I would appreciate any advice on how to proceed or if the proposed configuration is even achievable.

Answer 1

Photoshop files of 1GB+ can eat up memory and scratch. And the more drives for scratch, the better.
Some of the limitations are with the bus, bandwidth, and 'swapping' code in and out of different cores that is inefficient.
Compilers can do some, but from the time new hardware (8 cores) to seeing improvements to compiler, and out to software (applications) and OS, can take a year or more but provide in the neighborhood sometimes of 40%. In which time, newer designs will change the equation. Caching and VM will improve with Leopard, but beyond that...?
So... back to "read world" IF you are in the habit of working with 1-2GB images, then a pair of Raptors for boot is helpful, AND 8GB and more of RAM, AND 4-8 drives for scratch. (Think of those Sonnet Port Multiplier controllers and Fusion 500 style case for 5 drives on one port).
If you work with files smaller than 500MB range, your needs are cut way down.
150GB Raptor boot drive. Small. subtract 25% for minimum free space, 140GB formatted, kind of tight for some. But it handles 60% well.
The outer 30% of 465GB (RE2) is also fast and good performance. I partition large boot drives to keep the OS and apps contained in the outer 1/3.
Mac Pro Memory Usage and Performance
If your work flow means doing more than one thing at a time on your Mac Pro, then you will see significant gains if you spend extra to get the 8-core version. Our Photoshop CS3 actions were completed 39% faster on the 8-core when we had 3 other apps busy crunching. This advantage emerges in spite of the memory bus limitations of the 8-core Mac Pro.
http://www.barefeats.com/octopro3.html
CS3: Justifying 8-Cores
http://www.barefeats.com/octopro4.html
Pshop Test G5 Quad 16GB Raptor RAID
Photoshop and multi-core
http://blogs.adobe.com/scottbyer/
Mac Pro 2GHz 4GB 10K Raptor 23" Cinema   Mac OS X (10.4.9)   WD RE RAID Aaxeon FW800 PCIe MDD-G4 APC RS1500 Vista