The performance improvement demonstrated by the new 45nm CPUs over their 65nm predecessors is much more significant in games. The top Phenom II X4 processor runs 20-25% faster than Phenom X4 9950. However, we remember very well that the previous generation Phenom processors were actually so slow in games that new quad-core AMD solutions can only compete against junior Intel CPUs from the Core 2 Quad Q8000 series.
Nevertheless, we believe we have to remind you that quad-core processors cannot reveal their potential in most contemporary games yet. However, unfortunately, we will see the dual-core 45nm AMD processor no sooner than in June. Therefore, the best choice for a mainstream gaming system will still be Intel Core 2 Duo.