Opteron Overclocking on ASUS SK8N

Strange as it might seem, but ASUS SK8N mainboard offers some overclocking-friendly functions. Although this product is strictly oriented for workstations, ASUS couldn’t help implementing a few brand name opportunities for CPU overclocking.

BIOS Setup of ASUS SK8N is based on AMI microcode and is very similar to BIOS Setup of the newest ASUS mainboards on i875 and i865 chipsets. The BIOS Setup has a special page containing major overclocking tools and the possibility to change FSB frequency and processor Vcore.

The clock frequency multiplier seems to be locked in Opteron processors. At least, ASUS SK8N doesn’t allow adjusting it. As for the FSB frequency, it can be increased from the nominal 200MHz up to 300MHz with 1MHz increment. Also ASUS SK8N lets you increase Opteron’s Vcore from the normal 1.55V up to 1.65V or even 1.75V.

A separate page of the Setup is devoted to Vdimm adjustment: you can raise this parameter from the nominal 2.5V to 2.6V or 2.7V.

The AGP bus frequency is set separately, and can vary from 66MHz to 77MHz with 1MHz increment. Also BIOS Setup of ASUS SK8N increasing Vagp from 1.5V to 1.6V or 1.7V.

We decided to overclock our Opteron 244 working at the nominal 1.8GHz frequency with the help of the available options (the multiplier was set to 9x, the FSB frequency equaled 200MHz).