Intel Xeon E5 2603 v2 's Advantages
Lower TDP (80W vs 215W)
Xeon 6556P B 's Advantages
Released 11 years and 5 months late
Higher specification of memory (6400 vs 3)
Newer PCIe version (5 vs 3)
Higher base frequency (2.3GHz vs 1.8GHz)
Larger L3 cache size (144MB vs 10MB)
More modern manufacturing process (5nm vs 22nm)