Overclocking Graphics Card

I've decided after much debating not to replace my computer yet (very tempted mind, especially with all the talk of C2D & C2Q CPUs etc). So I'm stuck with my trusty P4 3.0Ghz Northwood (@3.4Ghz) and Geforce 6600GT AGP graphics. The rest of the spec is as in my "System" below my username. Cooling for CPU and GPU is with a Zalman Reserator 1 Plus - water cooled but fanless.

I'd like to get a little more juice from this as I've just bought Command & Conqueror 3 and want to play it at a reasonable resolution. So my two questions are?

1. How do I go about overclocking my 6600GT? Is it worth it?

2. Do you think I can overclock the CPU any more? Stability is vital but it has been running at 3.4Ghz for over 2 years now and temps are 27-28C idle and up to 38c at load.

CPU overclock won't really get you much benefit. GPU overclocking is more likely to, though you'd be better just spending 50 quid on ebay for a better card, and you'll have a much better result.

Even with overclocking (download coolbits then the controls will appear in the nvidia control panel) the 6600GT isn't going to be up to much in C&C3.

It all depends what kind of memory chips you have on your Graphic card. Not every GPU is good for OC.

Apart from coolbits you can use RivaTunner can download here

Lots of informations on guru3d website