Hi guys,

it's been ages since I posted here, but I recently discovered the forums again, and I could use some help.

I recently purchased a new quad core phenom II system with a (pretty power hungry..) sapphire 4870. I am really happy with it.

However, I also recently purchased a wattmeter, and I was amazed at how much power my new quadcore uses, compared to my other desktops. It's not strange, since most have onboard graphics, older processors, etc. I really expected it.

But I went experimenting. I downloaded ati tray tool, and underclocked my GPU in 2D mode(because who needs the power when browsing the internet anyway..) and reduced the power my pc uses from around 170watthour idle(it's pretty normal these days, I think) to 130. It automatically clocks it back to stock speeds when a game is loaded.

That got me thinking. I usually (over)clock a pc in the BIOS, but if I could find a tool that would underclock my pc, but reset it to default speeds and voltages when gaming, this would be pretty handy.

Now my question is: is there any tool that can underclock and undervolt my CPU while I'm at my desktop, but return it to stock speed while playing a game, just like ati tray tool did for my GPU?(I would also consider a tool that can just 'overclock' in cases of e.g. 3D applications, and underclocking my CPU standard from the BIOS)

thanks for the answers

I'm not sure about a utility that will underclock your CPU when you're performing any task in specific, but most decent non-proprietary motherboards will allow you to throttle your CPU during periods of inactivity as a whole. When load is introduced again, the speeds are kicked back up.

It does that automatically...the new phenom II processors automatically bring all four cores down to (if I remember) half speed. A single semi-demanding app will spark all cores to full though because of performance issues related to vista threads jumping around into power saving cores.

Thanks for the replies.

However, an underclock does not cause any less power consumption per se, it's the undervolt that goes paired with an underclock that does it. afaik, that's not happening....

@hellokitty[hk]: Ahh, Cool'n'Quiet totally slipped my mind.

@Exonimus: Reducing the clock frequency of a chip is almost always going to result in power savings and lower temperatures. Regardless, I believe Cool'n'Quiet decreases voltages anyway. You can read about the technology here. If you want to monitor your frequencies and voltages check out CPU-Z.

thanks.

Yeah, I knew those programs, and C&Q should be enabled, but I'll disable it and see if my power use on idle is indeed higher. I admit, that also slipped my mind :P

You see, I already tested underclocking and undervolting itself, and the undervolt resulted in less power usage, but the underclock didn't. The underclock only made a lower voltage possible.

Anyway, if cool and quiet does that, it's fine as it is now.

Thanks again.