I go to great lengths to try keep my XP 2000+ cool. I have a dual fan PSU to suck out all that heat out from the case and a copper core fancy heatsink to get it away from the CPU.
The trouble is, the bigger the heatsinks get, the closer they get to the PSU in most midi tower cases. Now, with a single fan PSU all that suck from the heatsink fan is either pulling against a flat piece of metal on the PSU and inch away, or, if it’s perforated, a grid with air being sucked the other way through it. With a dual fan PSU the second PSU fan and the CPU fan are pulling directly against each other. This can’t be an efficient way of doing things.

I’m trying and experiment, prompted in part by the heatsink design (sorry, I don’t know the name of the heatsink) not just being a open set of fins but a sort of square tube with holes on the side to regulate how the air gets in or out. I’ve turned the fan on the heatsink round so that it sucks air in from around the heatsink and directly out through the PSU, working with the second CPU fan. I’ve only done this for an hour but the temp has gone from down from 62 Deg C to 54. Not only that but the top of the case feels much cooler.

Now I’m not sure about other heatsinks, but this seems to work well so far.

Anybody had similar experiences?

A lot depends on what heatsink it is and what your case cooling is like. For the most part heatsinks are designed to have the fan blow down on the heatsink, but there are heatsinks that work better with air being drawn through them such as certain models from Alpha...they usually come with a shroud around the heat sink. I have spent a lot of time trying to find the best cooling with my setup and here are some ideas.
1. Focus first on your case temp. Get a cheap external/internal temp like from radio shack and place one probe as close as possible to the area with your cpu, but not in the direct path of any strong air flow. Wire it through the case so you can close the side cover. Use the other probe near the air intake of your case. Then run your system for a while and compare the two temp readings...outside and inside. I have managed to get mine so inside is only around 2.5 F degree's higher inside then outside. You should try to get a little bit more air into the case then what is being drawn out. It is suppose to help keep dust out of the case, by blowing air through all the loose panels in the case rather then dust being pulled in, but thats not written in stone. In my case the front case fan draws in, rear draws out, 2 side fans draw in, PS fan draws up...PS rear fan draws out. The side fans total are around 50 CFM, the front and rear are around 40 CFM. The power supply fans don't really do all that much for the case cooling. I would also focus on cleaning up the case for better airflow if possible. You could also try a cooling duct in the side of the case to focus outside air into the cpu fan. I think I am gonna try that also.

Hi Alan,
I think the easy answer is a full tower case with fan in the top back to extract the hot air that should rise naturally. The trouble is they’re a bit big to fit in the kids bedrooms. My full tower is running a 1.33 Athlon at 34 Deg C.

The other problem is the design of midi tower cases. Many have air vents on the side panels and back which does not allow you to get a definite air flow through the case