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From mobile devices to the desktop - AMD offers CPU throttling for everybody

It's always a good thing to not waste electricity, even if you're not relying on a notebook-battery. Even at home, on your desktop you might want to consider slowing down your CPU when it's not doing anything, and by that saving some electricity and producing less heat.

My new CPU, an AMD Athlon64 X2, has Cool'n'Quiet, which is, you could say, the desktop-version of PowerNow!. It can reduce the voltage and frequency of your CPU and increase it if needed.

The kernel offers the cpufreq-interface for this. With the cpufreq-utils you get the userspace-part of cpufreq, which is used to set the governor and frequency of the CPU. The governor is something like a profile. The performance-governor always runs on full speed, the powersave-governor on low speed.
In order to save power when the CPU isn't busy but have full speed when it's doing something the ondemand-governor can dynamically adjust the CPU-frequency according to what's needed.

As far as I can see Intel doesn't seem to offer frequency-scaling for it's desktop-CPUs, which I think is a shame. CPU-throttling is good, and seems not to have a big impact on overall performance. I can live with having the CPU switch to turbo-mode first when I start doing something that needs some more power.

Comments

Actually, Intel Core 2 Duo

Actually, Intel Core 2 Duo has this too as I've been using frequency scaling. Only recently the cpufreq stuff is complaining something is misconfigured or not supported, but considering I used it, the CPU supports it.

Intel C2D's spend less power overall anyway though.

No they don't I looked at

 

No they don't

I looked at some benchmarks and AMD x2 always comes out better Smiling

Well I remember

Well I remember differently, but that there could be benchmarks where X2 comes out better doesn't really surprise me because the differences are basically semantics. Both are quite energy efficient and both support frequency scaling. I don't really care about the semantic differences as I'm not fanboy, don't worry. Eye

In terms of value for money

 

In terms of value for money I have preferred AMD over the recent years, technologically I have nothing against Intel, my first, second, fourth and fifth CPUs were Intels (486 SX-25, 486 DX2-80, Pentium MMX 233, some PentiumII) and my notebook runs on a CoreDuo (not Core2 though).
Actually I have to admit that I don't really know the current prices for all that stuff. I just went there, wanted an AMD and got one. So I don't know how much I would have payed for a comparable Intel-system, but I guess it might have been more.

Anyway, what's important is that the box works, and, to get back to the topic, though Cool'n'Quiet it can even be scaled down when it's not necessary to run with full speed. My CPU seems to support 3 speeds, 1GHz, 1.8GHz and 2.1GHz. But I have to admit that I have never seen 1.8, since either my box isn't doing much (like browsing the web) or it's working it's a.. off (like compiling EasyLFS).

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