ok so the e8500 has 2 cores, each running at 3.16@ stock settings
the q6600 has 4 cores, each runnig at 2.4 @ stock settings
its really give or take
right now a dual core like the e8500 will do better in most things because they are optimized for dual core cpu's. in the future more things will be optimized for quad core cpu's making the q6600 better in the future
now if u oc the q6600 to 3.16 the same as the e8500 at stock the e8500 will still prolly be faster cuz is the new 45nm, that is unless u are using a quad core optimized program
also if u want to overclock the e8500 is a godly overclocker ppl can run them up around 3.8-4.0+, the q6600 on the other hand, if u get a good one(low vid), can do around 3.6-3.7 but they get pretty hot.
another thing to think about is that the q6600's now days are more commonly coming with higher vids, so more ppl are spending more money to get a q6700 or q9550
btw a vid is the stock voltage ur cpu uses to operate, the lower the better, on a q6600 the lowest ive seen is a 1.20v vid(i had one
) but now they are rare to find when u buy one new. but if ur not gonna overclock vids dont really matter
so it come to this
dual core: better right now
quad core: better later