I know how you feel Paul, with not wanting to kill what seems to be a "rare" processor now........by my specs you can see that I'm in the same boat as you are ('cept I run Socket 754). I have been running about a 5% overclock for the past 6 months now ....temps are very good under load with stock cooling.......mine normally runs 2.4 gHz and has been fine at 2511-2515 with normal idle temps of 38.5C while online as I write this note now. While not as good as the 90 micron technology in the Socket 939, I feel the improvement of the speed by overclocking is OK, considering I have less info paths on the 754 and limited by the 130 micron tech. I could go for more, but I have no idea where I'd be able to get another Athlon 64 3700+ ?
Hello Ken....!
Like you I am quite proud of my little processor....

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...My Socket A, AMD 2600 XP Thoroughbred!....

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It automatically defaults to run at a 166 MHz Bus speed to give me about 2.1 GHz...
Increasing the 166 FSB in BIOS slightly, to speed it up a bit, sometimes causes a lock-up, and a successful re-boot involves clocking the Motherboard back to 100MHZ again....

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At the mo' my processor is running a 64*C (145*F) just working my 2D desktop....
...goodness knows what it's temperature is when a running a complex 3D Game (Stalker)...

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I recheck my thermal compound every now and again to make sure it is applied correctly but it has no effect in reducing the temperature...My heat sink is a large Copper block, with large aluminium fins, and a variable speed fan.
None of my local stores stock Arctic Silver 5 thermal compound, which I wanted to try out to reduce the temperature.
Quite what a difference a few "speed cycles" more would make to the overall performance, I don't know, but I really don't want to risk destroying the 2600....'cos there are no more left in the World...

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LOL...

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Paul....getting all hot and bothered...

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P.S. My room temperature averages 68-72*F.....
...if I sit very still...

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Win 8.1 64-bit. DX11. Advent Tower. Intel i7-3770 3.9 GHz 8-core. 8 GB System RAM. AMD Radeon HD 7700 1GB RAM. DVD ROM. 2 Terra Byte SATA Hard Drive. Philips 17" LCD Monitor. Saitek Cyborg X Fly-5 Joystick. ...and a Briggs and Stratton Petrol Lawn Mower.