So finally I got the 2x1GB modules I ordered and damn, Apple should really reconsider selling such a machine with only 1GB, multitasking works so smoothly and Parallels flies right now, I have enough memory to run WinXP and WinVista virtual machines (each with 1GB) simulatenously while having tons of applications open in OSX and of course, I have the processors to back all that up 
To anyone with Mac Pros, do yourself a favor and upgrade to 2GB at least.
Also on a sidenote, Windows Vista (through bootcamp) now works perfectly and man, it flies as well, the experience index tells me I have a 4.4 machine because of graphics but its a 6.0 (out of 6) machine in terms of CPU and memory. Vista won't run (succesfully) on a Mac Pro with a 7300GT and only 1GB of RAM, it needs 2 or more to work with full videocard acceleration (BTW before you bash Vista, this is a Mac Pro only thing, PCs and other macs with 1GB or less work fine).
I can't wait for the Parellels team to implement 3D and multi processor support, once they do and with a powerful card (hopefully nvidia or apple will release mac 8800s or a hack comes out to use the card in OSX) games will run incredibly well, right now, XP virtual machine with 1GB doesn't feel much slower (if any) than native XP in bootcamp, Vista feels a lot slower for obvious reason but once 3D acceleration is implemented, man, Apple will owe Parallels TONS of switchers.
To anyone with Mac Pros, do yourself a favor and upgrade to 2GB at least.
Also on a sidenote, Windows Vista (through bootcamp) now works perfectly and man, it flies as well, the experience index tells me I have a 4.4 machine because of graphics but its a 6.0 (out of 6) machine in terms of CPU and memory
. Vista won't run (succesfully) on a Mac Pro with a 7300GT and only 1GB of RAM, it needs 2 or more to work with full videocard acceleration (BTW before you bash Vista, this is a Mac Pro only thing, PCs and other macs with 1GB or less work fine).I can't wait for the Parellels team to implement 3D and multi processor support, once they do and with a powerful card (hopefully nvidia or apple will release mac 8800s or a hack comes out to use the card in OSX) games will run incredibly well, right now, XP virtual machine with 1GB doesn't feel much slower (if any) than native XP in bootcamp, Vista feels a lot slower for obvious reason but once 3D acceleration is implemented, man, Apple will owe Parallels TONS of switchers.