Underclocking

I was thinking about the requirements for a HTPC being low power and silence. I hadnt really considered the possibility of underclocking the processor before. So Im sat here with my E4300 running at 600MHz with a FSB of 100MHz on a 6x multi. I havent minimized the voltages (just stuck on auto) so the temperatures arent as low as they should be, Id be interested to know the differences in power draw. SuperPi 1M calculation takes an rapid 1m36s.

Vista runs fine, its not quite as slick as at 3GHz but videos play fine and internet explorer runs flawlessly. For a HTPC I think this would be a viable option for a low power pc and with a passive cooler it would be near silent.

Any opinions?

Quote:

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Originally Posted by ***soul-edge***

i leave it on downloading crazy amounts of files.

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legally i hope...

@OP
underclocking drastically improves power draw because of the nature of it, i can't give any exact figures because i havn't really done it myself...(more power to the beast and all that :rolleyes:)

@soul-edge whats your powerdraw at stock like? just so it's easier to make a comparison.

Quote:

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Originally Posted by ***soul-edge***

the system i have is underclocked everynight as i leave it on downloading crazy amounts of files.

1.4ghz works out about 24 watts per hour on my system.
i think that would be alot more efficent.
my multiplyer is also unlocked, i can overclock with the multiplyer as well.

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I think you may have put the wrong units in there... You probably mean Watts or Watt Hours rather than Watts per Hour.

24 Watts per hour is saying 24 Joules per second per hour or 3600 Joules per Second squared, so if you were running for 1 hour (3600 seconds) and using 24 Joules that is equivalent to drawing 0.007W (Joules per second) to power your PC (24 Joules in 1 hour).

If you meant 24 Watts (or 24 Watt Hours) that is equivalent to 86400 Joules per hour and far more reasonable but still very low for a full system.

Seeing as you are 96 soul-edge it seems you are going a bit senile in your old age lol.

Watts measures energy usage over a period of time (J/s) same way as speed measures distance over time (m/s). Watts per hour is pretty meaningless. Watts alone describes rate of energy usage. A common unit for energy however is the KiloWatt Hour which is power (in KW) x time (in hours) which results in an energy unit.

Perahps I'm wrong, but I would have thought that there were three things involved here:

1. Clock - power has a linear relationship
2. Voltage - power has an exponential relationship
3. Use - downloading files will use little CPU power, while running, e.g. Orthos, "maxes" it. I'm not sure how this actually affects the amount of power used though.