Mac Pro Memory type

[tbob]

I've got a brand new Mac Pro with a minimal 2GB of RAM, here, and I'm looking to throw in some newegg magic...

I've read everywhere that any memory I add should have a good heatsink, which is easy enough to spot, however I'm wondering whether things like timing and latency much matter? I'd like to have a total of 16GB in the end, so I'm wondering which configuration will be the fastest?

4x4GB?
8x2GB? (no room for expansion)

I know it has to be DDR2 800, but how about voltage? timing?

Thanks in advance, oh wonderful shepherds of hardware wisdom!

 

[theblackbox]

the memory has to be an fb-dimm. you can't just use regular ddr2 memory. check out OWC (other world computing) for good deals on ram. i have 4x2gb and 4x1gb for 12gb ram in mine.
getting 8x2 is a lot cheaper then 4x4.
make sure the memory is apple certified. they have big heatsinks because the memory controller is on chip.


if you have the 320gb hd that came with the base model, get something faster and bigger for your primary, and either ccc or superduper your install, and move that 320 away.

when i got mine i put in a wd black 1tb, a spinpoint 1tb, a wd 750 , and moved the 320 to the 2nd slot, put vista 64 on it, and have never been happier.
i have the spinpoint in the first bay, and it is much faster then the seagate 320 they give you.