As thread title states, both oc'd to their maximum potential, what would yield better price / performance ratio? I am upgrading after 2 years and have fallen out of touch with the latest CPU results for gaming.
 
- Intel Core 2 Duo E8400 LGA775 'Wolfdale' 3.00GHz (1333FSB) - Retail - £187.99
- Intel Core 2 Quad Pro Q6600 "Energy Efficient SLACR 95W Edition" 2.40GHz (1066FSB) - OEM - £140.99
 
Also, what mobo chipset / mobo would you recommend with both?
 
Please remember this is a 100% gaming machine.
 
Thanks,
 
Callum.

I would take a look at the MSI P35 Neo2-FR, Good value with a heatpipe cooler, IHC9R southbridge and all solid capacitor design.
 
Its basically the same board as the P35 Platinum minus the firewire and a couple of the rear SPDIF connectors

With the e8400 you might get 4 GHZ with a good overclock.
I would go with that at the present time, because you are into gaming.
The Q6600 has four cores, but few games are able to use all the cores.

You have got to be kidding, right?  This has been beaten up time and time again here on THG and elsewhere. The E8400 series is faster at present and a great choice for a pure gaming rig but both will OC past the point you can see or feel any real world difference.  Why not go for  the E8200 for a better price/performance ratio?

Yeah This has been beaten up.  And maxed overclocked these two actually game about identical right now.  At low res cpu scaling settings there are games that both can win over the other.  Max OC e8400 probably provides the higher 3dmarks if that's your game.
 
But really at those prices there is only one good option IMO.  Why on earth pay that much more for the e8400?  It should cost less not more!  Priced the same or less Q6600 for sure IMO.  

it all just depends.  the are both pretty much fast enough to run anything you can install and run.  just buy the cheaper one.

i just built a PC for a friend and it had a q9300, that a right beast i bilieve that it cost him £180.
 
if you can find a deal like that i can only reccomend this processor.
 
The reson i would choose this processor is becasue it has all the new technologies it is both 45nm and a Quad.
 
i didnt bench it properly, but in a work unit (folding at home) of 5000 it did a fram every 13 seconds, thats fast.
 
although out of e8400 and q6600 i would go for the e8 becasue the 45nm is FAST-FAST. and operatate at relatively low temps.
 
hope some of this helps

I have the Q6600 and I simply chose it for more future proof as I'm tired of building computers every year.....its fast works great multitasking and plays games great...so the 8400 might beat it out a frame or 2 its still more expensive than the Q6600 and you can get another set of ram in its place...

Very true, the last to consider is the E8200
- Intel Core 2 Duo E8200 LGA775 'Wolfdale' 2.66GHz (1333FSB) - £117

Heh.. I still see the price perspective differently of the E8400 and Q6600.
 
I did buy mine for $235.  E8400 $209.  Now I look at it as how much per core:
 
209/2=$104.50
235/4=$58.75
 
Then I compare that to my E4400 which I did spend $126 bucks:
 
126/2=$68
 
So all in all, I felt I did okay.  I guess I could have gotton it cheaper, but then it would be that much longer before I had it in my system.  

Bloody hell do you guys get it easy in the States... your prices are crazy!  

At that price, get the Q6600. Quad applications are coming out fast, and then the Q6600's performance lead over E8400 will be massive. E8400 delivers higher performance on single or dual optimized applications because it can overclock higher, which means better performance on the short term, before applications go quad. If E8400 cost less, it would be a good deal. But at the much higher price you cited, it makes absolutely no sense.

I almost chose a Q6600 - but I went with the E8400 instead because of my needs and future-proofing concerns. I need the performance for gaming, and very few games take advantage of quad core processors. The Q6600 is basically the quad version of the old E6600 - since most games aren't quad capable, you're basically getting the same performance as the E6600.  
 
Besides, 2.4Ghz @ 65nm is going to start looking really old and clunky in a few months, even with quad cores and over-clocked. The Q6600 lacks SSE4, and 65nm is starting to look how 92nm did about 15 months ago. There is no way around the fact that the Q6600 is now an obsolete chip.
 
 
Personally, I would now get a minimum of a Q9450 if you must have a quad core.

Piffffff....
 
Seems to me dual core is getting old.  
 
I'm soooo happy I got a quad!!
 
But then I kinda miss my E4400, although I got parts on the way to rebuild it.  

 Way to go, you win First Place. ..... best laugh I've had all day.    

Gonna go with the Quad, thanks for your help guys.

 
Thanks.
The sooner you Q6600 fanboys buy out Intel's stockpile Q6600's, the sooner the rest of us can get a sweet deal on a Q9550. See ya'all in a few months when you're upgrading. Make sure you get a 1600Mhz FSB capable motherboard so you can replace that old 1066Mhz FSB Q6600.  
 
 

 
Better yet is the e8400 fanbois that keep the thing way over retail price recommending it no matter what the cost.  Just lets us smart people grab the better / more expensive Q6600 for less.    

I got my Q6600 for $200, oc'd it to 3.6, and it's freakin great.  It will encode the crap out of video with all four cores working.  I'll keep it until we all have to switch platforms for nehelem next year.  Once you go above 3.2, you won't really see much gain with regards to fps in games.  Being that Crysis is the only game that my system can't do maxed out, I ran some tests to see if cpu speed matters at 1680x1050.  Once you go above 3.2, it doesn't, not on my 8800gtx anyway.

CPU never really helped games. It's been the gpu that's made the difference for at least 10 years now. The reason for this is simple; fps are hot stuff and there's only a limited number of things a person can focus on with a gun . Only a few games take advantage of the cpu and they usually have lots of "units" that need to have their stats constantly updated and are all AI thinkers.
I like the dual core but not when a comparable quad is cheaper or the same price.