I recently upgraded bios on my KT3Ultra mobo and noticed added item in power managment in bios: CPU Halt Command Detection. It works pretty well, a bit better than CpuIdle (= in games). What I would like to know is, if this option is commonly available on other popular mobos, such as Nforce2, etc.

Current temps: Duron 1G + Zalman AlCu: 34c, Case 35c, no special equipment or mods, ...yet.

It became available to me , with a BIOS upgrade for my NF7-S 2.0 (a Nforce2 board).
It works very well - better than Vcool.

I think it was the update to version 1.6 that did it for me.
I'm now running 1.7 because that includes other advantages like more stable and overclock friendly memory.

Version 1.8 is out but it offers nothing interesting enough for me to upgrade just yet. I'll wait for the next version.

Interesting, I can't seem to find it in my BIOS though, I'm using Abit NF7-S 2.0 and BIOS version 2.0.