Any gain in replacing 7cm cpu fan with 8cm?

[pmv]

Trying to reduce the noise of my very noisy PC. Have AMD 64 (X1) with stock cooler.
Don't want to replace heatsink, too nervous I'll mess it up (get poor thermal connection or put too much pressure on cpu or something), but wondering if there's any benefit (or risk) in using one of those 7-8cm adaptors and putting an 8cm fan on the existing heatsink. Clearly, there is a huge choice of 8cm fans, compared to 7cm ones (of which the choice is basically nil), and which, presumably, could give same cooling for less noise.

I can imagine lots of things that could go wrong though. Do those adaptors make sense, do they maybe produce resistance/turbulance that cancels out the benefit of the larger fan? Does the fact the fan will be a bit further away cause problems? How would the auto-speed sensing thing the motherboard does be affected? I read somewhere that some stock AMD fans have their own temperature sensor.

Is there more to it than just total air-pushing capacity? Maybe it would do better than the stock fan at idle but be unable to increase speed sufficiently at load (stock fan goes from 3000rpm to an ear-numbing 6000rpm).

Also the 7-8 adapters seem available only in the US or on ebay. By the time I make up my mind they'll probably be unavailable again.

Another thing I'm confused about is whether its worth getting a fan controller for the 3 12cm case fans. The specs for those fans say they are 19dB. But the cpu cooler goes from 45 to 60db, and, as I understand it, 3db increase means a doubling of volume.

Ergo, the CPU fan is as loud as 100 case fans, so what's the point in reducing case fan speed?

I'm sure that can't be right, though. Are the case fan specs lies?

 

[Zepper]

Putting any type of reduction adapter on a closed bottom heatsink is an exercise in frustration as it just increases the back-pressure. If the heatsink is radial with an open bottom, then it may work, but you may want to start the fan at a slower speed to get the flow going and then crank it up.

.bh.

 

[WoodButcher]

For the minimal expense involved I would certainly try it.

 

[zagood]

Your case fans may not add that much in decibels, but they'll add a different pitch to the sound. Sound quality is not only based on decibels.

Regardless of that, you need to read some instructions, bite the bullet and replace that heatsink. Ignoring the inherent mounting problems, Zepper's got it right with the backflow issue.

-z

 

[RallyMaster]

I say you get a new heatsink altogether. Socket 754/939/940/AM2 is one of the easiest mounting systems to work with and it would only make sense to get a better cooler, to be honest.

 

[pmv]

Fair enough, I just have a phobia about messing with the cpu. I'm not a serious techy, Have installed every PC component at some point, inc mobo, except cpu. Maybe I will bite the bullet sometime, or maybe I'll just pay someone to do it for me, or wait till next cpu upgrade.

I'm not 100% convinced about alternative cpu coolers. Some cooler review site I was looking at (frostytech) reviewed the stock cooler and compared its stats with 30 or so others, and though it recommended replacing it, the actual figures (I even plotted them on a scattergraph) didn't really show it performed all that badly compared to all the others. Only a couple of the other 30+ definitively reduced the noise levels while cooling as well or better. Most seemed pretty loud by that site's figures. Some performed worse than the stock cooler. Still, if I do upgrade I'll have to research it to pick one of the few quiet ones.

 

[RallyMaster]

Uh...give us a budget and we'll find a good one that's easy to mount using the default mounting mechanism. At least that's how it works here...