Without the ability to overclock the Q6600 he is crippled by it for gaming.
I usualy have mine at 3.6 and can put it at 3.8 when needed. Just for the sake of doing it I ran it at 2.4 and run 3d mark 11 with my modest 5770 and it was sad to say the least. It may be time to save 200 more and replace the mobo with and h61 mobo and an i3 2100 series with 4 gb or ram. the performance would be tons better. Not exagerating it would be worthwhile better. If he sells off the ram and CPU he could maybe recover 100 dollars q6600 still sell quite high concidering it's 3 generations old and the price of ddr2 has gone up..... just suggestions but gaming at 2.4 on the q6600 with modern games is unacceptable for quite a few new games