How room temp. affects processor temp. (graphs)

@graysky: Thank you very much for this valuable observation and the effort you put in collecting the data. Would be great if you can take a few more data points in the range of 26-30 C ambient, if possible.

Allow me to represent the data a bit differently, by examining the relationship between the ambient temperature and deltaT.

As was observed, the C/W is not fixed, but rather increases with ambitent. However, one wonders whether the relationship is actually linear. Maybe an inverted S-curve centered around a design point (23 Ambient = 25 enclosure?). I think the inclusion of the low temp observations and the use of CPU core temps rather than deltaT may have masked what is actually going on.

Using the last two observations, one may guess that an increase in ambient of 1C further, may actually result in 1+ increase in deltaT, which means 2C increase in core temps per degree ambient (core0).

And if the behaviour is actually non linear, it may get worse very quickly. The implication being that summer temps may hold some surprises and would require caution.

I'm curios whether the 1:2 ambient:CPU change in temperature ratio is a limitaion of air-cooling per say... or merely a limitation of air-cooling inside a PC box...

I don't know where in the world you live and if you get any extreme weather... but it might be interesting to see what happens when your room temperature hits 35º C or even 40º C (86º F - 95º F)...
I find that some systems have a cooling peak and if you go beyond that point... the system is saturated and overwhelmed, to the point that the internal heat skyrockets out of control...
This would indicate that a 1:2 ratio is directly dependant on the capacity of your PC cooling system...

As a test, perhaps you could take off the side covers of your PC and use a 37cm (15 inch) floor/desk fan to cool your system...
Nobody would want a huge fan like that on a permanent basis... if for no other reason than the sheer noise and dust build-up...
1 test during the midday heat and another in the cool of the night should suffice to see whether the ratio is still maintained...

Also, try using CPU Burn... 1 iteration for each core... which should max-out your CPU heat potential... (100% CPU usage NOT= maximum CPU heat).


:):D:eek:
Pascal

My room temps now in the summer have reached up to 37C. I can assure you that the increase in CPU temp is not linear, but it's not that far from it either. Sucks to not have A/C. So frikin hot in here. I'm lucky I watercool, if not I could never maintain my OC during the summer. Not that winter is very cold here, but at least temps don't go as high as 37C! :eek:

Although now that I think about it, my other PC is air cooled and I still maintain the OC during summer. It's of course not as high as the OC in my watercooled rig, but still 3.2GHz on an E6600 in an air cooled rig with such high room temps is not bad at all IMO. ;)

@mechmech: interesting graphs you've generated. If you do a linear regression line on those data, what is the R^2 value?

Quote:

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Originally Posted by graysky

So what does this mean and why do you care? Well, using these rules of thumb, if it's currently 70 °F in your room, and your average load core temp is 65 °C, you can expect that to change by roughly 0.8 °C for every single °F your room temp. change. Say your room hits 80 °F. Your load core temp should increase from 65 to 73 °C which may be unacceptable to you and you might want to adjust your o/c accordingly. This is just an approximation based on my system. Your mileage may vary...

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Do you find, or notice, a similar correlation for CPU idle temps...

The results being true, are a little disturbing... since you're at the mercy of the weather and seasons...
I don't always have a need for seriously OC speed but when I do... then it would be nice to know that it is on-tap... not so if it's a particularly hot day out there.
I considered a little pro-active cooling like A/C assisted aircooling when necessary or even a peltier water-chilling boost (for naturally aspirated water cooling)... but condensation can also become an issue...

I guess it's all par for the course in the quest for a dream/extreme machine...


:):D:eek:
Pascal