I am building a new computer with an AMD Athalon 64 X2 3800. I was wondering if I needed to apply a thermal compound to the bottom of my heatsink/fan. The heatsink/fan came with the CPU. The heatsink/fan has a small pad on the bottom already that looks like some sort of thermal compound. Also if it turns out that i do need to apply a thermal compound what is the best one? If someone one could answer this for me that would be great. Thanks.
That "thing" that comes with a stock heatsink/fan is not a thermal compund exactly, it's called a thermal pad, use it if you want it does exactly what thermal paste does. But if you prefer paste/compunds go with arctic silver 5 unless someone else has something better they want to suggest. I'll be using AS5 with my build.
The thermal pad works very well. It's a lot of work to replace it, so only do it if you need to lower your chip temps by 2 degrees.
I only use AS, when I'm lapping the bottom of the heat sink. I find that the pad does a better job on large dings in the hsf base.
as far as the advice to use the thermal pads. I would highly recommend against it because remember. Those 4 dollars for the compound is definitly worth it even if the temp goes down 2c because remember that adds to the ambient temp inside your case as well. That temp can be bad for other components that arent cooled as efficiently as your cpu for example your hdd.