I have my q6600 OCed to 3.4Ghz, with 8GB of memory and a 7950 3GB graphics card.
Plays a new game like evolve at high settings.
bf3 at near max unless a 64 player server.
SCII at max, and I see no reason why it will not play the 3rd installment of SCII at max also.
All at 1080 and running two secondary monitors to show temps, fps, and load.
I build this computer in 2008 and am amazed at how well it has held up. Upgraded memory from 4 to 8 a few years back. In the past year or so I have added the 7950 (it will be this systems 3rd gfx card), And a SSD really kept it up to speed.
If you want to sell it I would be happy to buy it for a low price,