[MikeLip]

Correct me if I'm wrong (just trying to help).

I believe you should go with the 2x2Gb ram for now. (suggested above).

Until we get a 64 bit executable, 4Gb is the ram limit for Pro Tools native systems. No advantage on PC or Mac to go >4Gb presently even when running 64bit o/s. Its an Intel 32 bit limit for 32 bit apps. Right?
(edit: oh wait I'm wrong, I guess and extra 2Gb for o/s overhead on 64bit o/s would be nice eh to prevent disk paging?)

Oh and AMD vs Intel, not sure but I think they're coming to within parity of each other recently. I usually read up on pc review sites on the latest. I have both AMD and Intel rigs for Pro Tools; HTPC; Gaming; Server. All work great and were cost effective when I purchased them. And I run gigabyte and asus.

edit: Thanks Tom for those links! I'm reading furiously :)

Ta,
Mike.