I have been battling noise in this computer for awhile now. Several months ago it started making a loud pitched whine. The whine would change pitch depending on cpu use. After doing some research I learned about soft mounting and how sometimes the metal screws connecting the fan to the heatsink can cause vibration throughout the case which increases noise. I went ahead and removed the screws and mounted the stock fan to the heatsink using double sided tape on all 4 corners. This immediately lowered the whining noise, so much so that I was kind of shocked. Anyways, over the past week the whining noise has started to come back some, nowhere near as bad as before but enough to annoy me.
According to the specs the stock fan is 5000 RPM with a noise output of 44.3 dB. 5000 RPM is pretty high isn't is? The speed is always the same no matter what I'm doing. I've looked into Speedfan to try to change it but it doesn't do anything. It says the speed is around 2100 RPM but I don't know if that is correct or not. The computer is an OEM HP so no options to change speed in the BIOS. The computer runs pretty hot as it is. Usually 60-75C depending on load. From what I understand these older Slimlines run hot though and I've had the computer for 5 years without any problems.
What fan should I be looking at replacing it with? I want quiet as possible. The options on Newegg for 70mm fans are pretty sparse. From what I understand this size fan isn't really popular so the pickings are slim. Should I be looking at a 80mm fan instead? It wouldn't fit the currect bracket but I could just double sided tape it to the heatsink like I'm doing now couldn't I? There are a lot of quiet and highly rated options in the 120mm range, but that wouldn't fit in my case would it?
I'm trying not to spend any more than $20-30. If a $10 fan would be just as good I'm fine with that. Thanks for any help and suggestions on what I should do.