GTX 560 Ti Performance question.

I've recently purchased a GTX 560 Ti and I read a few forum topics off of google which said that the q6600 2.4ghz paired with this video card will hinder it's true performance.

Now unfortunately, I'm using a q6600 2.4ghz and my PC is made by HP so I highly doubt I will be able to overclock.

Here is my system: http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01...

-I upgraded the PSU to modxstream pro 500 watt
-ram to 4gb instead of 2
-I'm thinking of getting a new fan (the arctic rev 2)

I understand that I won't see the 560 ti's full capability, but will I be losing A LOT of performance or just minor?

Thanks!