Problem with CPU fan overspeeding

[retsiger]

Hi!

Yesterday I bought a new power source to my computer. After installing it, I found out that my CPU fan speed was spinning with much higher speed than before, although CPU temp is around 44 C as before.

The fan speed is now 2000-2100, while it should be less than 1700 rpm, according to it's instructions. The noise is almost unbearable, when it should be only 19 dB. Also before power unit change, the speed was over 1800 rpm, but the noise didn't catch my attention as much as now.

The old PSU (if that stands for power supply unit?) was 250W, the new one 400W. The CPU fan is plugged to motherboards CPU_FAN plugin.

A couple months ago I upgraded from Athlon XP 2200+ to 3000+ and also changed the CPU fan at the same time. Could it be, that my motherboard is trying to adjust the CPU fan speed to the same speeds as the old fan needed to provide enough cooling? With the old 250 W PSU it couldn't supply the CPU fan with enough power for higher than 1800 rpm, but the new 400 W PSU it may be able to give more rpm:s? I have also noticed, that the new PSU feels much warmer than the old one. Maybe this suggests that the CPU fan "sucks" all the power it can get from the PSU?

CPU fan model: ClacialTech Silent Breeze 462 III (if I recall correctly)
MoBo: GA7VAXS (came with Fujitsu-Siemens Scaleo 600, (bought 2002))
CPU: AMD Athlon XP 3000+


Any ideas, what to do?

(Sorry for bad english)

 

[Nitestick]

the psu would be warmer than the old one simply because its more powerful, physics suggests that more heat will be generated. as for the fan my guess is that it was underpowered by your old psu.

 

[retsiger]

the psu would be warmer than the old one simply because its more powerful, physics suggests that more heat will be generated.

Hmmm... But if the system that draws power from the PSU is the same as before, shouldn't the power consumption, and thus the heat production, also be the same? I might be wrong, though.

as for the fan my guess is that it was underpowered by your old psu.

If it was underpowered before, then why was it's speed higher than indicated in it's instructions? Also the noise level is much higher than it should be. As I said, the noise level SHOULD be 19 dB, while now I would assume it's more than 40 dB, comparable to muffled speech.

 

[Nitestick]

its odd but to me it seems logical. but trust me, i can tell you that the higher powered the psu the hotter it will be. my old 300w generic piece of crap psu was cool to the touch. but my new 480w antec runs at over 50 c, hotter than my cpu.

 

[retsiger]

Ok, I'll trust you

The noise is weird, though. I'll borrow a fan speed control device from my friend, and see if the problem can be solved with that.

 

[Nitestick]

seems like a good idea. good luck. if you're worried about it see if you can borrow a similar psu to test.