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Power/Energy efficiency

Last response: in Overclocking
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Anonymous
a b à CPUs
a b K Overclocking
April 24, 2001 2:01:24 PM

There is a lot of talk about overclocking, but what about underclocking.

Why, you might ask. Because of energy efficiency. The athlon 1.3GHz is 90W. I find this a stunning energy use. There are 100's of millions of computers in the world and reducing the power use of the CPU is both easily attainable and would make a significant contribution to reducing power usage.

From a personal point of view, I would be able to remove the fans from the CPUS and thus get an additional reduction in power and reduction in noise.

I would like to leave my PC on all the time so that I can dial into it and have my telephone calls handled by it, but at 300W overall, this equates to £300 per year in electricity.

If I could get the power consumption down to about 50W in the short term, this would be great.

What I would like to see is the power consumption of the CPUs directly presented along with the other headline information.

When it comes to overclocking (and underclocking), the power consumption at the relevent frequency and voltage.

Thus: is it cheaper to overclock or buy a faster CPU becomes a meaningful question that can be answered.

And did I mention the savings I, and companies across the world would make in reduced air conditioning.

Let me put this another way

Don't care about power and cost
=> cpus that produce lots of heat
=> lots of air con to make life comfortable again
=> no power left in California.
=> No sympathy here. Its self inflicted.

Maybe its time to think about the cost of electricity.

Regards to all and don't take it personally.
April 26, 2001 12:43:43 AM

You'll not drop your power consumption by underclocking (directly), you'll do it by cranking down your voltage. When you crank down your voltage, you'll be forced to underclock to maintain stability. Just like overclocking, there will be a physical limit to how far you can go. It still takes .3/.7 volts to switch a transistor, no matter how cool you get it.

As far as efficiency, no. It won't be, unless you're just surfing the web. If you're trying to zip down a file that takes 30min at 1ghz, it'll take 1hr at 600mhz. You'll get the most out of your system by running it as far as it will go; your processor takes as much power to run as your hard drive, cdrom, fans, mainboard/pci/agp/memory. Spin down your hard disk, and make your monitor go to 'suspend' (<3watt) after 1 min. Your monitor easily pulls 500watts (14inch), probably closer to 800 (17-19 inch).
April 26, 2001 4:00:33 PM

I think you should check your figures regarding monitor power consumption.
Unless my monitor is very unrepresentative of the norm then I believe you may be substantially overstating power consumption.
My monitor is a 19" Iiyama Vision Master Pro 451 (A902MT), the specifications are 138W max.
I do agree however about the savings to be made by enabling
monitor power management features via the operating system:
Stand-by mode: 10W max
Suspend mode: 10W max
Active-off mode: 3W max

Another possibility that might be worth investigating is the 'wake on ring' feature that seems to allow a suitably equipped system to be powered up when a ring signal is detected by a modem with this feature.

I have no experience of using 'wake on ring' so cannot say how well it works.

I do have my system (based around Asus A7M266 + 1.2Ghz Athlon) set up to go into 'sleep mode' when I press the sleep button (either on my keyboard, or on system case).

This puts my monitor into active off (3W) and also powers down hard disk drive, and reduces cpu power consumption
by entering a 'Halt' or 'Stop Grant' state and disconnecting the processor from the system bus.

Wake up time is a few seconds (the time it takes to spin the disk up to speed.



<P ID="edit"><FONT SIZE=-1><EM>Edited by paulcalmond on 04/26/01 12:35 PM.</EM></FONT></P>
Anonymous
a b à CPUs
a b K Overclocking
April 28, 2001 12:25:43 PM

Check out radiate, it'll calculate the theoretical wattage for most chips at various voltages and wattages.
Tiny little program but very handy especially if you are thinking of getting a peltier and have water cooling installed like me.

I can resist everything except temptation
!