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Case Fans - Some Interesting Results

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pbs

Registered
Joined
Apr 15, 2002
Location
UK
I have a P4 1.6A OC'd to 2.4 @ 1.65V it is fitted with an Alpha PAL HS and
Delta Fan in an ABIT TH7-II Raid. The case is a Cooler Case Tornado with 6
YSTech 80mm Fans and the PSU is an Enermax 435W model with fan speed
control. I also have a further 4 Papst 40mm Fans cooling the RDRam.

I decide to carry out some thermal tests on the system since all those fans
make the system a little bit noisy. I used the spare floppy drive blanking
plate to mount 4 Single Pole Double Throw Centre of switches which I
connected to allow the fans to be supplied with either 12V, 5V or OFF.

The Switches controlled:-

Switch 1 - The two fans on the SIDE of the case which Blow IN.
Switch 2 - The FRONT and REAR fans which blow IN and OUT respectively.
Switch 3 - The two fans on the TOP of the case which blow OUT.
Switch 4 - The 4 Fans cooling the Memory.

The CPU Fan ran at full speed at all times as did the Fans on the PSU (
which can be varied between about 1600-3200 RPM)

I used CPU Burn In V1.1 to conduct the test the results of which are:-

Only CPU Fan running CPU 48C Case 36C
All SLOW (5V) CPU 42C Case 32C
All FAST (12V) CPU 40C Case 31C

The noise difference with the Fans running at 5V instead of 12V is
considerable and the temperature rise is not that much greater. The slow
running fans seem to be able to change the air inside the case quite well.

I will have to repeat the tests with the CPU running at 2.6 but that
requires 1.85V which means a BIOS Flash to a less stable BIOS which
sometimes suffers the Cold Boot problem.
 
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