Back in April I assembled a new system;
large mid-tower case
amd 6400+ dual core
msi k9a2 platinum motherboard
msi 8800gt video card
650 watt power supply
one 120mm case fan sucking and a 92mm and 80mm fan blowing
stock cooling on the cpu, vga and psu.
All of the above running windows 32 bit xp.
Initially I found that the system ran fine at idle and with the usual software ( Turbocad, Paint shop pro and others). The cpu ran at 45c and the video card at 55c.
When I ran fsx the temps soared to 65c and 75c respectively. Obviously too high, so I started to research the problem. What I found was a lot of acceptable solutions. This is what I decided on.
First I purchased a Accelero s1 rev. 2 from Arctic Cooling. Although this is a passive cooler there is an optional turbo module (two Fans) which I choose to add to the video card. The install was very easy and the results were better than I hoped for. Now my 8800gt card stays at 43c under normal use and tops out at 46c in fsx.
I was so pleased with the results I once again turned to Arctic Cooling for my cpu and purchased the Freezer 64 pro. Again the install was painless and the results were more than I hoped for. Under normal loads the cpu is at 31c and in game play it rises to 48c, well within what I think are acceptable limits.
Since my original upgrade I have overclocked my system up to 5 percent and have very little increase in temps and it is very stable. I see no downsides to my choices and the prices were very reasonable.
One note that I would mention is that the video card cooler is quite large and you need to find out if it will fit into your case. Arctic Cooling has dimensions for this unit on their web page.
I hope my experience has helped. I will try to answer any questions if needed.
Paul