Forum Core i5-750 - 2 66GHz compare Core 2 Quad Q8400 - 2 66GHz

it depends on the budget for the whole build.

the i5 will offer slightly more grunt, but a system built around a phenom II will be cheaper, allowing you to spring for a more powerful GPU which will ultimately give better gaming performance.

They are very similar CPUs.

Here you have a comparative chart between them:

http://www.anandtech.com/bench/default.aspx?p=102&p2=10...

Your title says Q8400.
I have a Q9400 and it will OC to 3.8GHz easily, as will the i5-750. At those speeds the i5 is still around 20% faster than the Q9400.

At this point the intel quad cores are relatively expensive. If they fit in your budget then great, but from Tom's recent $750 gaming build it seems that the less expensive AMD chip offers good enough performance for gaming and saves you money that would be better put into your graphics card(s). And don't get me wrong, I'm NOT an AMD fan but for some people they still make sense.

if you are conscious about power consumption, go with the i5-750 (95w TDP) if not, get the Phenom II (TDP 125w). the perfomance difference aint that much therefore you probably wont even notice it during gameplay.