Need help finding a quiet replacement cpu fan for slimline htpc

I have an older dual core AMD Athlon Brisbane 1.9 cpu on an HP Slimline. I want to make the system quieter but I'm not sure if I should be looking at replacing just the cpu fan or the fan and heatsink. The current stock fan is an Asus 70x70x20mm (specs listed in link below) and the heatsink is also an Asus which is bolted down to the motherboard in a square pattern with screws at all 4 corners.

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.


http://parts.digikey.com/1/parts/172...12dd-tp10.html

Or should I just try a fan controller?

http://www.newegg.com/Product/Produc...Ltd-_-35118217

Yes, it's a standard 4 pin connector.

I'm not really understanding the diagram. The cables look the same to me. Is the $6 adapter I posted basically do the same thing? Would you recommend lower speed over getting another fan?

Never mind, I don't have that setup after looking at it again. I obviously have the wires coming from the fan into the connector, but where I plug it into the pins are just sitting in the motherboard. There's no way to change anything.

Still looking for suggestions. I played around with Speedfan a bit more and got it working. I can slow the stock fan to around 1100 RPM which is definitely quieter than before, but still makes a little noise. I don't know if I can get my system any quieter, but I'm willing to try a new fan for $10-15 if it's going to help. Good 70mm fans are hard to find, but I found this Nexus which I heard gets good reviews. I'm not sure if that one will be adjustable with Speedfan though. Any more suggestions are appreciated.

http://www.amazon.com/Nexus-70mm-Real-Silent-Case/dp/B003PNLRLU/

Thanks for the recommendation. What made you choose that model over the million others out there? I read the reviews on Newegg and the overwhelming majority complained that it was extremely difficult to install, taking up to an hour in some cases and needing an extra hand. Did you have any problems? The stock one in there now in extremely easy to take in and out. It just screws down on all 4 corners and that's it. I've never replaced a heatsink before but I don't understand what could be so difficult. I don't see the 4 feet like mine on the one you posted so I'm not sure how it gets secured. The 70mm fan I have right now is almost touching the side grill as well, but the fan faces the front of the case not the side. I don't know if it would fit either but right now I have the case off anyways because it runs too hot after I set the fan to 1100 RPM. The CPU is at ~65-70C under 10-20% cpu usage. Some people in the reviews said it only gave them a few degree improvement over stock while others said 20+ so I don't know what to believe.

The thing I care about most is making it as quiet as possible. The computer is 5 years old so if it eventually dies due to heat then I've got my moneys worth and I'll just get something else.

The stock fan I have right now is actually the Delta AFC0712DD, which looks to be the same as the AFC0712DB, just custom branded for HP or something. I'm limiting it to ~1100 RPM with Speedfan, but even that is not silent. Am I just asking for too much? Is there no fan out there that is 99% quiet during normal conditions? Would a brand new Delta be quieter than my 5 year old model? Do they get louder with age? Do I need to mount it another way, vibration dampening screws or something? Right now it is doubled sided taped at all 4 corners with a 1/4" gap between the fan and heatsink. I did this a few months ago after some research showed that the metal screws were vibrating through the heatsink to the cpu. Every time cpu usage would go up or down a high pitched and extremely irritating whine would occur. I've eliminated that by removing the screws and mounting with x2 sided tape.

The fan I have now at 1100 RPM isn't *loud* by any means, but the whirling/humming noise is completely audible from 9 feet away and loud enough to be annoying.
Edited by StinDaWg - 6/10/12 at 12:40am

That one is 3500 RPM and does not have PWM to control the speed. Wouldn't that be louder than what I have now?

So the one that is slightly thinner and pushes slightly less air should be quieter at the same RPM?

I'm still a little confused on whether I should be getting another PWM fan and limiting the speed, or just getting a so called "low noise" fan at a fixed speed.

You have any ideas where I can buy that model? A google search brings up a few stores I've never heard of, and Newegg but it's been discontinued and the reviews are from over 4 years ago.

Just bumping to see if anyone else has any other suggestions before I make a purchase. I'm either going to get the Delta AFB0712HHB mentioned above with PWM function or get something marketed as "low noise" like the Nexus Real Silent 70mm and then buying a fan controller if it's not quiet enough.

Well, I don't think anything larger than 70mm will fit in my case. As it currently sits the left side of the fan sits right up against the side panel. I have maybe half an inch between the other side of the fan and the power supply, so I would have to jerry-rig it if even possible. It would probably fit fine without the side panel on.

That being said what recommendations do you have for those sizes?

Aren't those 37 and 47 CFM numbers rated at full speed though? I've increased the stock Delta fan I have to 5000 RPM just for testing purposes, and it sounds like a jet engine revving up for takeoff. There is no way anyone could live with something that loud. It has to run at ~1500 before it's acceptable and I have it at the lowest it will go which is 1100 now. I guess what I'm getting at is if I'm never going to run the fan at full speed what does it matter what the CFM rating is?