DDR400 (= PC3200) is the nominal memory for use with an 800 MHz FSB CPU .
Microstar may give a list of approved memory on their web site
(
www.msi.com.tw). Or, use Asus (
www.asus.com.tw) recommendations for memory
for their P4P800 or P4C800.
An 865PE mainboard like your Neo 2 needs to use memory in matched pairs to
get the full memory bandwidth. (I don't know about the MSI board, but my
Asus P4P800 -also 865PE - can work in single channel mode as well.)
"Matched" means same size, speed, memory timings, etc. It might be wisest to
buy memory sold as matched, but I'm getting tolerable results from a couple
of no-name 512 MB DDR 400 sticks (using Samsung chips) that were purchased a
few months apart.
It's also possible to run DDR333 (PC2700) memory, at 320 MHz, or 4/5 of the
FSB (Front Side Bus) frequency (multiplied by 2). I doubt that it'd be
enough cheaper to justify the loss in performance.
Some arithmetic: the 800 MHz is from a 200 MHz FSB, "quad pumped", whatever
that may mean. (It means something like four operations per clock tick.) The
Pentium memory bus is 64 bits (8 bytes) wide, so that works out to 6400
MB/s. A single DDR400 DIMM normally operates at 64 bits wide at 400 MHz, or
3200 MB/s. A pair of them gives 6400 MB/s. (You won't see that level of
performance in real applications, but it's cool, all the same.)
If you're feeling adventurous, consider overclocking. Set the FSB to 250
MHz; the CPU will run at 12X250 = 3000 MHz (3 GHz). Set the memory
multiplier to 4/5, and the AGP/PCI buses to 66/33 MHz, to keep then running
within their specifications. I doubt that you could easily push a 3.2c that
far (to 4.0 GHz), but the lower-end (2.4c, 2.6c) 800 MHz chips are known as
good overclockers.
HTH.
Bob Knowlden
Spam dodger in use. Replace nkbob with bobkn.
