Hello,
I am to decide between E8200 and Q6600.
OC is my first need and also I want to know even bus1066 make the Q6600 inferior to E8200's bus (1333) or not?

on the contrary, the 1066FSB allows for more OC headroom as there is more space to overlclock. For example, a 10 multi and a 266 bus speed produce 2.66Ghz. 8 multi and a 333 bus speed also gives you 2.66Ghz. The extra bus speed makes no difference in performance, BTW: http://www.extremetech.com/article [...] 071,00.asp

So a higher multi is better because a few bumps on the bus speed will get you a higher clock, basic math. The q6600 has a 9 multi, with a 1066 FSb, all you gotta do is raise it to 1333 and you've got 3Ghz. So, 266->333 yields 2.4Ghz->3.0Ghz. The difference in bus speed was 67mhz. the yield was 600mhz on the clock. now if you up the e8200 bus speed by the same amount, 67mhz you'll get 400mhz, or 1600Mhz FSB. now that would yield:2.6Ghz-?3.2Ghz. Diff:540mhz on the clock speed. A noticeable difference. Bottom line: shoot for the Q6600, plus its quad.

get a Q9450

It also depends of the limit of your Motherboards FSB. If you MB spec. is 1333 FSB it may or may not be capable of 1600FSB or >

OOPS. Sorry. +1 for the Q6600

Thanks for your replies guys.
My MB is ABIT IX38 Quad GT. So I do not have limitation toward bus support(it supports 1600)
My limitation is money as Q6600 and E8200 are close, but the 9xxx series are a bit expensive for me. I already have an E6550 and I wonder if it makes a good difference for me to go for Q6600 , because I have the opprtunity to upgrade just
NOW.

so you run out of FSB headroom faster on the 1333 Wolfdale.

I would say if you want an extreme amount of overclock, get the e8200. If you want to video edit, play games like crysis and get a decent amount of overclock, get the q6600. If it was me I would get the q6600, only because more multi-threaded games and apps are on the horizon.

most ppl get their q6600 at 3.6Ghz on aftermarket air cooling, and thats only 400Mhz bus speed. To get 3.6 on the e8200, you would need the bus speed at 475, quite high. Also

Q6600-220$
http://www.newegg.com/Product/Prod [...] 6819115017
E8400-200$
http://www.newegg.com/Product/Prod [...] 6819115037

So the e8400 has a 9 multi, is better than the e82, and costs less than the q66