look into your BIOS
NF2 MB: BIOS release 1.7 for NF7/NF7-S v1.0/1.1/1.2 NF7-M v1.2
4. Added "CPU Disconnect Function"option on chipset to turn on/off C1
disconnect.

if still not working [cpu idle for 10 minutes] then try
8rdavcore
http://www.hasw.net/8rdavcore/