As for performance difference, it can be quite large at stock, especially in video encoding using latest software that take advantage of sse4. So the more expensive q9550 can be worth the extra. Q6600 does overclock a larger percentage respective to it's lower stock clock (typically from 2.4ghz stock to 3.6ghz, a 50% increase), resulting in similar performance when both cpus are oced. So if you oc, the price gap is not worth it.
Also, q6600's higher 9x multiplier (or q6700's 10x) helps with oc, 1600mhz fsb = 4.0ghz at 10x, 3.6ghz at 9x, 3.2ghz at 8x, 2.8ghz at 7x. Check what fsb your motherboard can handle.
I am in canada, greater toronto area, and the prices i poseted are from pc village http://www.pcvonline.com/ place right across the street from me and i find they have realy good prices
and the cpu's i showed are all retail packages including the heatsink
Keep in mind, you should not use the stock heatsink Intel include on expensive, hot running quad. It's barely enough for dual, and just not enough with quad. Full load temperature run too high even at stock. Get aftermarket hs instead. http://www.frostytech.com/top5heatsinks.cfm
My Q6600 arrived just yesterday and I can't describe how pleased I am with it. Only had 1/2 hour before I had to go out so I've only taken it to 3GHz on my P5K-e so far and not really stressed it. I'd go for the 6600 if you plan on OCing.
What do you use your computer for primarily? At 2.7+ your chip should run any game and application flawlessly, provided you have a capable video card. I would only upgrade if you video encode/transcode, or have an addiction to the couple of games that are optimized for 4 cores.
Why not upgrade your video card to a 4850/4870, then a year or two from now, go with a Nehalem platform?
my current cpu is e4500 at 2.7ghz its slower bus speed even with overcklock i can't reach a bus of 266mhz or 1066 fsb, and less on die cach 2mb total, game like supreme commander against 3 ai's starts to slow down to a crawl after 1 hour of playing and i also want to speed up Flight Simulator X, my current monitor is lcd tv at 1360x768 and i think my 8800gts(g80) can still hold its own, tell me if my assumptions are wrong? i do ocasionaly play crysis, and other gpu intensive games, but until now they are all working flawlesly
don't automatically assume 3.6 overclock for the q6600. I had two of them: one did 3.6 no sweat, the other couldn't handle 3.2. it depends on VID(among other factors), which you can't tell until you pop it in the machine and start up.
regardless, there's no wrong answer to this question. you'll be happy with either choice. just look at your budget and decide what you can afford.
The Q6600 is a very nice CPU for the price itself. If you do video encoding en multitask allot you might aswell buy the Q6600. You can't really go wrong for the price, and these things are very stable, you can get them to 3,0ghz easily and remain stable. Thats with stock cooler... I recommend to get a nice aftermarket cooler , Hyper TX2 , or Xigmatek rifle coolers.
Go with the Q9550...
It has a L2 cache of 12mb as opposed to the 8mb on the 6600.
I found it way better than my original QX6700..both temps and overclocking wise. Heading up now to QX9650..4ghz here I come
nagitiated from 99.95 to a low price of 82$ hope thats a good deal newegg has them for 20$ more
as soon as i put it in i will reply with the overcklock i got
i got q9550...
i have it at 3.85 ghz and since the architecture is about 10 % better than a kentsfield its about equal to a 4.235 ghz kentfield... and since my mobo can only get a stable fsb of 453.... (w/o super high voltages) 8.5 * 453 = 3850 versus 9 * 453 which is 4.077
so for me the q9550 was better than the q6600... the q6700 may have been a better choice... but at a certain speed i don't think clockspeeds well over 4 ghz matter