Opteron 3320 EE 's Advantages
Released 2 years and 9 months late
Higher base frequency (1.9GHz vs 1.866GHz)
More modern manufacturing process (32nm vs 45nm)
Lower TDP (25W vs 95W)
Xeon E7520 's Advantages
Higher specification of memory (1333 vs 3)
Larger L3 cache size (18MB vs 8MB)