Thanks for the link.
As i benefit a lot from the use of ramdisk as scratch disk, I would llike to know if anybody handling huge file using a workstation with lots of ram.
My observation is : the bottleneck of photoshop is the scratch disk and the use ram instead of physical drive can make it fly.
I have been using an 8 core Mac Pro with 16GB of RAM for about one year now. I also handle many images in the 1 to 4 GB range.
PS on OSX does automatically use available RAM as RAM disk in a dynamic and flexible way. It is overall real fast (I have 3 Raptor set as 2 independant scratch disks - one for PS, 2 for stitching application in Raid 0 soft).
A few months ago I would have advised a switch to the Mac platform, but:
1. I am still not convinced by the performance/stability of Leopard at this point of time (I have kept my workstation above on Tiger but use Leopard on a familly iMac),
2. Adobe has announced that PS CS4 for Mac will not be a 64 bits application, which is a total bummer and real shocking news.
All in all, you best bet is to wait for the release of PS CS4 for Win 64 and to get a lot of RAM indeed. I would personnally not want to spent too much time with Vista (I have it installed on a VM Ware virtual machine on the Mac), but your mileage may differ.
Overall though, I have found that the 2 factors that allowed me to save the largest amount of time recently were:
1. Using a very fast SCSI320 Raid 5 6TB external mass live storage solution,
2. Upgrading to PTgui 8.0 beta3.