The performance in contemporary games is first of all determined by the performance of the graphics accelerator. And as you can see from the obtained results, $60-80 CPUs cope pretty well with the load created by gaming applications and provide acceptable fps rate. It means that Athlon X2 and Pentium processors may suit quite well for inexpensive gaming systems.
However, Pentium processor family is overall a little faster than Athlon X2 7000 series. Strange as it might seem, they lose to the old Athlon X2 6000 released almost two and a half years ago.