Memory won't run 400MHz

[VanTheMan]

My system hangs when I tell my A8N-SLI Deluxe to run my Corsair XMS 3200 at 400MHz. I have two 512s set up for dual-channel. The timings were set at 2.5 7 3 3. I think they're supposed to run 2 6 2 2. It runs fine at 333MHz at 2 6 3 3.

Also, there's a 1T/2T setting in the BIOS. Which one should I be running? It defaults to 2T and it says 2T should only be used with unbuffered memory.

 

[CalvinHobbes]

There's no reason the memory shouldn't run at stock settings. It may be a problem with the motherboard or the memory. Can you run one stick at stock settings? Have you tried updating the BIOS?

1T would be the best choice.

 

[VanTheMan]

I'll try flashing the newest BIOS and running one stick. Thanks

 

[cubby1223]

Athlon 64's seem to have lots of problems running memory at ddr400 speeds. Since the memory controller is built into the cpu, I'd think the problem is with the cpu design instead of the motherboards. Like my own computer, recently for a few days I wanted to run 768mb ram (512+256) while I waited on a 1gb dual channel kit to arrive. Individually, with either stick the system could run at ddr400 speeds. But together they would only run stable at ddr266 speeds. Setting them to ddr333 caused some instabilities in XP, and trying ddr400 speeds I never got video to appear on the monitor & had to reset the bios to continue.

Now that I've got the new dual channel kit, it still autodetects to ddr333 speeds, but I can manually set the timings to ddr400 & 2-3-2-5 1T like the memory is rated for, and everything is running fine.

And it's happened on a lot of other computers, having ddr400 memory autodetect at ddr333 and having two mismatched ram sticks (in single channel mode) cause major system instabilities. I don't know if there's an answer, that's just what happens.