I had an old Socket-A Sempron 2200+ in my box, and decided to see what it could do with a stock cooler (it was a retail model with AMD hsink/fan). It's the 333MHz FSB model and I have 1.5Gb of 333MHz 'crucial' RAM. It's got a locked multiplier - 9x - so the effective speed is 1494MHz. I was sure that it could do better than that, so I started ramping up the FSB in 2-MHz incremements. It took all I threw at it and the temp. upped from around 52 degrees idle to around 56-58. Deciding just to go for it I pumped up the FSB to 200 (400) and sat back to see if the CPU and RAM could take it.

And it ran just fine - 1800MHz on the CPU and the 333 RAM overclocking to 400 no problem. My mobo does support CPU:RAM ratio's but I just left it 1:1 without issue (it's an Asus A7N8X-X).

Seems like the Sempron Thoroughbred core is actually pretty handy, over 300MHz overclock with a stock cooler and I didn't even have to play with the voltage or anything. The Crucial memory also seems good as it performs well above it's stated data rate. When I get a chance I'll post up my Vista windows experience index figures so you can see what difference it makes - I also fitted an Athlon XP 3000+ and clocked that a bit as well so you'll see the comparison.