If like me you were an early adopter of Core 2 Duo then you probably still have that old E6400 or E6600 rotting on your 975X, P35 or X38 chipset. And, truth be told, there isn’t anything shabby about this what so ever. There’s really very little you can’t do with these processors even now about 1-2 years after hitting the mainstream.
But your friends are now sporting 1333MHz or quad-core CPUs and getting a lot better performance in modern games based on UT3 or Crysis or CoD4. Physics is getting heavier and heavier in every game released and this still needs a beefy CPU for performance even if you have an 8800 GPU of some sort.
If you can stand to wait a little longer than the Q9450 is the answer for you. This is a Yorkfield core with 2×6M L2 cache (for a total of 12M), an 8x multiplier on a 1333MHz bus, and four 45nm cores running at 2666MHz each. I’m not currently sure what price it will fetch but it will run in the $300-$500 range. So finally an affordable version of the Intel top end processors which also support 12M L2 and 1333MHz FSB.
Is it absolutely worth upgrading from an E6600 or Q6600 or E3450 to this processor? That really depends on the rest of your system. I have the Asus Maximus Formula, an X38 board, some good RAM, and an 8800 Ultra. I’ve been playing the newer games and notice that CPU does start lacking sometimes so it seems like the next upgrade I’d need to make. If you need to upgrade your board or RAM to take full advantage of the Q9450 then you might want to wait until DDR3 becomes a bit more affordable before jumping in to a new processor. And certainly if you have an older video card then that should be your first upgrade since it’d yield the best gaming results for you. GPUs are always the most important for gaming.
Of course if you don’t do any serious PC gaming then you really don’t need any of this stuff. Even five year old hardware is fast enough to do anything else you need.