I purchased this mainboard soon after it was released and fitted it with
Corsair XMS2-5400 DDR2 RAM, P4 540 3.2E GHz CPU (D0 stepping), Abit RX600
XT-PCIE graphics card, and Creative Labs Sound Blaster Audigy2 ZS Platinum
Pro PCI card. I have 4 x 250GB SATA hard disks in two RAID arrays (using
the onboard RAID).

I then added watercooling using Asetek blocks on the CPU, VGA, and NB.

The best semi-stable overclock I can manage is about 240/3840 MHz.
This is done with the following settings:
VCo 1.6125V, DDR2V: 1.90V, NBV: 1.70V
CPU temp at idle: 45C, CPU temp at load: 56C, Ambient temp: 25C

On very hot days the CPU full load temp approaches 60C, whereafter the
machine normally crashes.

Whilst I can get into WinXP at 245 MHz it will not run stable under full
load.

Considering the speed of the DDR2 and that the temperature is still within
acceptable limits, I'm disappointed with the poor overclock ability of my
setup.

I suspect that the overclocked PCIe bus might be at the root of this
problem. Maybe the graphics card is sensitive to the overclocked frequency.
Or maybe the SATA disks cannot handle it. Reports on the internet about the
AA8 is a mixed bag regarding the overclock ability of this board. Some
good, some bad.

Am I missing something?

PS: I have the latest MB BIOS (ver 1.8).