Intel Xeon E5 2603 's Advantages
Lower TDP (80W vs 120W)
Intel Xeon E5 2686 v3 's Advantages
Released 2 years and 6 months late
Higher specification of memory (2133 vs 3)
Higher base frequency (2GHz vs 1.8GHz)
Larger L3 cache size (45MB vs 10MB)
More modern manufacturing process (22nm vs 32nm)