Power and efficiency

Stickman

Stickman

Stickman

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Joined
7 Jun 2009
Posts
394
Location
East mids.
I am running seti units on my i5-2500k, and Milkyway is keeping the 7970 toasty. I also have one of those ocuk energenie monitors so i can see how many watts the pc draws.

edit: oh, note that the CPU is currently cruising at just 4.4GHz to save a little juice - 4.6 doesn't seem to give me a noticeable improvement. :)

Typically the system idles around 80-90 watts, and peaks at around 160w in normal usage.

Running the distributed computing on all four cores and the graphics card as above it pulls about 350w... not bad.

The weird thing is, if I set boinc to use 70 or 80% of the processor cores instead of 100%... the power usage actually increases to about 380w.

Wondered if anyone else had ever watched the watts and saw similar things, and if anyone knew why?

My guesses would be:
a) the 750W PSU is much more efficient when higher loads are drawn.
b) the cpu being maxed out limits how much the 7970 can do, becoming a bottle neck.

Any thoughts? :)
 
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Milkyway shouldn't need much CPU time but since they updated the GPU app some users have had each GPU task using a whole CPU core. I get this on one of my systems but not the other two :confused: 350w also sounds too low for an overclocked CPU and GPU. I think my 7970 system is using about 380w with the CPU idle. What is your Milkyway username so I can look at your task details?
 
found you :) I can't see your computers though because you it set to hide them. Just lookup your tasks and check the task run time against the cpu time. The CPU time should be quite low 3-4 seconds. If the run time and cpu time are roughly the same then it is using too much cpu. You can also decrease power usage on milkyway by turning the memory clock down on the gpu since mw does not need high memory bandwidth. I managed to reduce the power consumption of my 2x6990 by about 200w by turning the memory down to 900MHz and it made no difference to the time per wu.
 
Here it is... run time is quite a bit higher. These are all gpu units so in theory used 5% of CPU, and 100% of GPU.

18oqi0.png
 
Your cpu usage seems normal but some of those runtimes are quite long for a 7970. 44s is normal for stock but some of those are taking quite a bit longer. Is your GPU usage staying at 100% or does it drop down sometimes?
 
Well the box is also used as a media centre.... running XBMC or gaming as needed... that might take some of the power and slow the WUs?

But of course when I was talking about the power usage I was just doing the seti/milkyway.
 
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