1792Mb RAM @ 166Mhz or 1024 @ 400Mhz?

Hey all.

First off, system Specs:

Mobo: 939Dual-SataII
CPU: AMD Athlon XP 3500+
RAM: (heres the problem/Question)
Vid: x1600 Pro PCI-E
Sound: Soundblaster Live! series
PSU: 465W
HDD1: 40Gb ATA/133 Samsung
Hdd2: 80Gb SATAII Samsung

Okay, I've got three sticks of RAM in there right now: 1g, 512Mb, and 256Mb. They are all labeled DDR400 (which means 200Mhz...right?). In my bios, when set to 'Auto', it sets it to 133Mhz. When I set it higher to 166 or 200, the comp either won't post or will but crashes.

What gives? I figure its a bad stick of RAM in there, because when I run the 1g stick at 200Mhz, it does it fine. My question is, will I get better performance out of keeping all 1792Mb in there at a lower clock speed, or pulling out everything but the 1024 and running it at 200?


Google