No. An i5 4590 which has 1/3 the amount of cores has much better performance (6300 vs 7200 in CPUmark). 4 stronger cores will beat 8+ weaker cores any day. Games on average use 2-4 cores with some using more (GTA 5), which means most of the processing power of the opteron would be wasted. The performance in games would probably be slightly worse than the performance of a Phenom II x4. You'd be much better off getting a FX 8350 or i5, maybe an i3 if on a tight budget.