I am unsure of which forum to put this in so please move me if wrong! OK. My system is as follows. Mac Pro 8x3.2 cpu, 16Gb ram, 8800gt gpu, 4xinternal HDs, 30"&23" displays. Plus the usual collection of odds and sods. My work is mainly in CS4 photo. and web based research. Question is for you ,I am sure very basic. What goes where for stable fastest operation? HD1 - should that just be the OS, or OS+ Applications or other? Where should my user file go? Do you get my drift? Is the default set up best for all or should I set this monster up a another way? At the moment:- HD1 - OS +applications, HD2&HD3 RAID ! (scratch) and RAID 0 (library backup, HD4-Library. It is the HD1 stuff that is in question? Thank you in advance.