This is a strange problem I think its related to having two cores. Here's my problem, the CPU will run in prime 95 on any of the 3 stress tests for 10 hours straigh(i quite testing, it never failed). But when i run HL2, it will freeze up at the same parts every time. When its at stock, it works fine. So i lowered it from 2.5 to 2.4 ghz thinking that it was a memory limitation having 4 dims filled, which is about the the max my old 3200 winchester had. Same damn problem. I played FEAR for a couple hours and it did not have any problems. Although i did not have time to test any other games. Any ideas? And how do i set processor affinity so it always does it automatically? I don't need to use both cores on non dual core optamized games, that will get rid of compatability issues, which i know my dc has some, especially with ground control 2, its BSOD's after a few minutes whether the cpu is set to stock or its oced. And its not the drivers, as the have the same everything when i had my winchester and that never had problems.
Gee, thanks for all the help and suggestions, but I figured it out. I did some more snooping and remembered the article on Anandtech about OCing the 3800 X2 for all its worth on a DFI NF4 infinity mobo, with 1gb daul channel. And i found in there article that when they tryed to OC the X2 with 4x512 they have massive failure, only small oc could be reached, and even then everything seemed flaky. However, OCZ is gratious enough to swap my 4x512's for 2x1024's due to them not performing when all 4 sticks are used. Apparently it is a common problem on A64 boards, i my guess is that it stresses the memory controller to much and maybe the ram as well. Right now i pirated 1gb of Corsair XMS 2-2-2-5 low latency from my older comp(3200 winchester, 9800 pro 128mb, 2gb 4x512 Corasir ram, A8V deluxe mobo). Mainly its a second computer as a backup, my younger brothers use it and buddies use it when come over. But its nice to have overkill ram in both systems, so now that i have to RMA my ram, i still have 1gb in each machine, lol.
Yea...actually getting your machine somewhat stable at those speeds is amazing...Most people can't do as well as you have. Assuming you stayed 1:1. I chatted with a guy in oc'ers forums who hit 250 2T with some patriot tccd stuff...but in that same thread another guy posted that he wasn't able to get any kind of oc with the same stuff.
The only ram that has been proven to run with 4 sticks at 400 has been the tccd stuff (coupled with 64 AMD processors...this doesn't apply to Intel), and even though you can run 400 in most cases, you have to move to 2T from 1T (3% slow-down or so...so a fairly important limitation).
2x1024 is almost always the best way to go, if you can.