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ibmkg · 07-26-2007, 01:03 PM

This is what I have practically observed:

When water temperature increases so does the CPU temp.

With full load, FAN running at 12V, the difference between room temp, and water remains constant i.e. difference of 2C (this holds true regardless of load at set voltage). The max CPU I have seen is 55C. The min is 10C above ambient i.e. 41 C (room temp when 31C). Water being 33C.

Turning off the fan, the water temp gradually rises i.e. linearly with load (that is understood).

Fan running at 5V, the temp remains constant with normal use (No gamming).
However, running say, NFS Carbon... The temp rises. The difference between air temp and water gradually increases.
I have noticed difference of 8 C max. My aim was to maintain the 2 degree difference of water-air.

This would work great in summers but I sense flaw in winters. Since CPU might be cool enough yet the fan would spin fast as it would sense greater difference (water to air ratio) under load.

-----------

Now I cannot directly control the fan from mobo since its a 0.8amp and my mobo supports 0.4amp max as per manual specs. I can use transistor but....wheres the fun in that!

Furthermore, I was thinking to design a software through which I could see the temps in windows and control the fan speed. That would make life easier since I could switch between performance mode and quiet mode.

Now you guys have to guide me. I cannot just stick LM35 near the cpu. I can but I doubt it would sense the actual CPU temp (I can use Arctic Silver’s epoxy, but again where to ‘stick’ it?). What are my options?

07-26-2007, 01:03 PM	#3
ibmkg Cooling Savant Join Date: Jan 2005 Location: USA Posts: 129	Re: Q. Making a FAN controller This is what I have practically observed: When water temperature increases so does the CPU temp. With full load, FAN running at 12V, the difference between room temp, and water remains constant i.e. difference of 2C (this holds true regardless of load at set voltage). The max CPU I have seen is 55C. The min is 10C above ambient i.e. 41 C (room temp when 31C). Water being 33C. Turning off the fan, the water temp gradually rises i.e. linearly with load (that is understood). Fan running at 5V, the temp remains constant with normal use (No gamming). However, running say, NFS Carbon... The temp rises. The difference between air temp and water gradually increases. I have noticed difference of 8 C max. My aim was to maintain the 2 degree difference of water-air. This would work great in summers but I sense flaw in winters. Since CPU might be cool enough yet the fan would spin fast as it would sense greater difference (water to air ratio) under load. ----------- Now I cannot directly control the fan from mobo since its a 0.8amp and my mobo supports 0.4amp max as per manual specs. I can use transistor but....wheres the fun in that! Furthermore, I was thinking to design a software through which I could see the temps in windows and control the fan speed. That would make life easier since I could switch between performance mode and quiet mode. Now you guys have to guide me. I cannot just stick LM35 near the cpu. I can but I doubt it would sense the actual CPU temp (I can use Arctic Silver’s epoxy, but again where to ‘stick’ it?). What are my options? __________________ NOTE: Suggestions are based on my perceptive. I could be erroneous. Therefore, no one has the right to criticize an individual other than rephrasing and or expressing his own annotations on the subject matter itself.