Power consumption with high CPU usage

[QuickSort]

I was wondering what difference there is between a typical desktop computer that uses a lot of CPU for number crunching compared to a computer that runs less intensive activities.

Would a desktop that averages 10% CPU usage use significantly less power than an idential desktop that averages 90% or would they both use roughly the same amount of power? I have tried to look up rough figures of power consumption versus CPU usage for a typical desktop PC but had no luck. Any ideas?

[jelli]

You will notice a difference in energy usage, I did when I was running the F@H Client, whilst running the client I used significantly more energy and ultimately had to stop because I couldn't afford to run it. Sorry but I can't give you any figures :(

[tsupersonic]

Yes, a desktop that averages 10% CPU usage would use less power than a desktop that averages 90% CPU usage. It depends on what kind of application we're talking about. If we're talking about gaming, and the CPU usage is pretty high, you have to figure in the graphics card is also drawing a lot of power too (graphics cards draw more power when under load compared to idle), so therefore the total system is using more energy than say if it was just browsing the web.

If you're worried about power consumption, you can look into the Intel Atom, Via processors, and AMD also has some low wattage processors. Again, it depends on what apps you're trying to run. If you're just browsing the web, doing office documents, then a Atom processor should be fine.

[hjf288]

With my comp idle according to Gigabyte Energy Saving Tool my CPU uses about 6.9 - 7 Watts.

At 83% CPU Usage it rises to about 32Watts

[GrimReeper]

  hjf288 said:

With my comp idle according to Gigabyte Energy Saving Tool my CPU uses about 6.9 - 7 Watts.

At 83% CPU Usage it rises to about 32Watts

Wow that seems pretty low considering a Intel Core 2 Duo has a tdp of 45W and the Quads and Core i7 are 90W+, not sure of the exact figure.

[Athlonite]

TDP and usage have nothing to do with one another but are related one is heat the other amount of power being used

http://en.wikipedia.org/wiki/Thermal_Design_Power

read that and you'll get a little better understanding of what i said

[Subject Delta]

You will always have some kind of difference between low and high CPU usage, but how big the difference is depends on the CPU. For example a power hungry CPU like a Pentium 4 would have a larger power usage difference between low and high load than say for example a 45nm Core 2 Duo.

  GrimReeper said:

Wow that seems pretty low considering a Intel Core 2 Duo has a tdp of 45W and the Quads and Core i7 are 90W+, not sure of the exact figure.

Most C2Ds actually have a TDP of about 65 watts, and the quads about 100-110w at stock clocks.

[+shift. MVC]

  hjf288 said:

With my comp idle according to Gigabyte Energy Saving Tool my CPU uses about 6.9 - 7 Watts.

At 83% CPU Usage it rises to about 32Watts

Doesn't make sense because if that were the case you could run your computer on a 150W PSU 'cause 32W at 83% load would give you less than 25% load on your PSU...

  Frank Fontaine said:

You will always have some kind of difference between low and high CPU usage, but how big the difference is depends on the CPU. For example a power hungry CPU like a Pentium 4 would have a larger power usage difference between low and high load than say for example a 45nm Core 2 Duo.

Most C2Ds actually have a TDP of about 65 watts, and the quads about 100-110w at stock clocks.

95W for 45nm variants, as well as G0 Revision Q6600m 105W for B3 revision ;)

[GrimReeper]

  Atlonite said:

TDP and usage have nothing to do with one another but are related one is heat the other amount of power being used

http://en.wikipedia.org/wiki/Thermal_Design_Power

read that and you'll get a little better understanding of what i said

I didn't realize. Thanks for the heads up :) I've never used tdp for measuring power usage I always used it to determine what to buy so I could use passive heat sinks without frying things haha :p I just assumed it was related but I was wrong :(

[hjf288]

  shift. said:

Doesn't make sense because if that were the case you could run your computer on a 150W PSU 'cause 32W at 83% load would give you less than 25% load on your PSU...

95W for 45nm variants, as well as G0 Revision Q6600m 105W for B3 revision ;)

Without a meter i cant really check but thats what the gigabyte tool says, Processor is Q6600 undervolted.

[Thirtythree]

  Atlonite said:

TDP and usage have nothing to do with one another but are related one is heat the other amount of power being used

http://en.wikipedia.org/wiki/Thermal_Design_Power

read that and you'll get a little better understanding of what i said

Actually, they are relatively close in fact.

http://en.wikipedia.org/wiki/CPU_power_dissipation

"Some CPUs (i.E. newer Intel-CPUs) have the typical power consumption defined as TDP and some (like CPUs from AMD) have the maximum power consumption defined as TDP."