Whats Faster for System Memory?

[BF2_Joe]

2 sticks of 512MB or 1 stick of 1024MB?

I thinking 2 512MB.

I have four slots to use i have two 512mb PC 3200 @ 400Mgz.

[dalemcalpine]

2 is better on newer systems.

[Gulf_War_Syndrome]

There are plenty of variables on this one.

Dual channel memory is theoretically better, but not always. If you are overclocking your Athlon64 for example, often you may not be able to reach as high a MHz (on RAM and/or CPU) in dual channel mode. If this is the case, you will need to run benchmarks (lower MHz dual channel vs higher MHz single channel) to really find out what difference it makes.
Pentium 4 CPUs really need as much memory bandwidth as possible, so dual channel will almost always be better in this case.

If the 1GB module has worse latencies than the 512MB modules, this will also make a difference.

[dalemcalpine]

Go here and look: http://www.tomshardware.com/index.html

lots of guides...good luck.