Why is it that overclocking a DDR2100 memory module to DDR3200 causes more heat than a normal(non-overclocked) DDR3200 module?

cuz ddr with pc2100 is designed to run at 266mhz not at 400mhz,, u cant drive Daweoo Lansos as fast as Honda Accord not cuzing any damage

woot! this is going to be hotter soon...

now seriously that is a extreme OC, you better buy 400mhz modules or DC your current 266mhz

Of course I'm not really overclocking that much . It was just an example. But I still don't get it, do they use different manufacturing for different speeds?

Yes they do... Even is you have a 266MHz DDR chip it still can work higher then that, there is a margin. How much the margin is we can’t tell, you have to test that your self. Old 266MHz chips will most likely not OC as far as a new 266MHz chips.

To over clock a older DIMM just try to rise the clock speed first, later look if you can rise the voltage from e.g. 2.5 to 2.7 for example, that can help too. Last, go for heat spreaders with frag-tape or some thing if overclocking is succes full.

You just have to experiment, only bad cooling and rising the voltage can damage the DIMM (other changes will not do much damage but it’s on your own risk).