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watts and c/w

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lilneel12

Member
Joined
Apr 17, 2004
i just looked at my sissoft sandra estimated cpu wattage and c/w and at 1.675 vore at 247fbs at 3.7 i am putting out around 120watts(goes up and down a couple of watts) and at .9 c/w and goes up and down .1

-how acurate and good or bad are these readings considering that my temps are 10C off in the first place and also, how can i calcultate the c/w??

thanks
 

greenman100

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May 18, 2003
Location
trying to keep all the magic smoke in
I doubt sandra is reporting .9C/W, b/c that would mean sandra is seeing 100C difference between temp sensors.

all sandra does is (CPUtemp-Motherboardtemp)/watts calculated

hardly accurate if any of the factors are off more than a couple %.
 

nikhsub1

Unoriginal Macho Moderator
Joined
Oct 12, 2001
Location
Los Angeles
lilneel12 said:
then how can i calculate the true c/w of my cooling?

thanks
You cant! Not unless you have seriously accurate equipment. Oh and the C/W value is a constant... it will not change no matter the heat input.
 

greenman100

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trying to keep all the magic smoke in
lilneel12 said:
then how can i calculate the true c/w of my cooling?

thanks


well, you can, to a point.

you can look at BillA and pHaetsus's tests of radiators and waterblocks, figure out what flowrate your pump is pumping given the head loss curves of the said waterblock and radiator

remember tehir tests are accurate relatively, not absolutely

if you don't know the difference, you have a lot to learn

good luck

check out procooling for good info
 
OP
lilneel12

lilneel12

Member
Joined
Apr 17, 2004
i get it now, but its too much to figure that out, thanks guys
 

nikhsub1

Unoriginal Macho Moderator
Joined
Oct 12, 2001
Location
Los Angeles
matttheniceguy said:
You can get the C/W from the thermal output, the temperatuere of the cooling air, and the temperatuer of the cpu.

There is a program called radiate that will do the calculations for you.
http://www.overclockers.com/articles430/

Another program called CPUpower is good for finding your thermal output.
Yeah in theory... still no better than guessing your temps though. There is no one here that knows the 'actual' temp of their CPU. What is reported and what is real are very different and there lies the problem with getting a true C/W.
 

greenman100

Disabled
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Location
trying to keep all the magic smoke in
nikhsub1 said:
Yeah in theory... still no better than guessing your temps though. There is no one here that knows the 'actual' temp of their CPU. What is reported and what is real are very different and there lies the problem with getting a true C/W.


pHaesus knows pretty close, he calibrated the on-die thermal diode.