Undervolting along with AMD Cool 'N Quiet?

[jrichrds]

I'm planning on purchasing a couple of the energy-efficient 45W AMD X2 Brisbane CPUs. Since the PCs will be on 24/7 and idle the majority of the time, I would like to maximize the Cool 'N Quiet feature of the CPUs.

I read on this page that if your motherboard doesn't have CPU voltage control, you can still modify the voltage with software like RMClock as long as you have Cool 'N Quiet enabled in the BIOS.

Has anyone done this to undervolt the CPU even more when it is in the energy-saving Cool 'N Quiet mode? It looks like the default voltage in Cool 'N Quiet mode is 1.1v for Brisbane processors. I'm curious if people have been successful setting it at 1.0v or lower.

 

[najames]

I think I have CNQ enabled on this system (Biostar TA690G & 3600x2). I run it under-volted and overclocked a little @ ~ 2GHz / 1.1V as I recall, currently 29.7C with a stock heatsink, but it is cool here tonight. It will run down to ~0.9V, certainly under 1V. I wouldn't worry to much about it, just get a decent board you know has voltage settings, set it up, and see if it works.

I honestly think this is the best system I have ever built. Stable at settings I didn't even think it would run at. Dual monitors even work on it in Linux using the onboard video only. LAN is decent and the chipsets aren't hot, can't say the same for the Gigabyte 690G rig sitting to my right. The Gigabyte will also undervolt a 5000 Brisbane nicely.

This is from Linux, reporting it is running at 1GHz now, looks like CNQ is working.
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 3600+
stepping : 1
cpu MHz : 1000.000
cache size : 512 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2