Intel Xeon E5603 's Advantages
Lower TDP (80W vs 105W)
Intel Xeon E5 2660 v3 's Advantages
Released 3 years and 7 months late
Higher specification of memory (DDR4-2133 vs DDR3)
Newer PCIe version (3 vs 2)
Higher base frequency (2.6GHz vs 1.6GHz)
Larger L3 cache size (25MB vs 4MB)
More modern manufacturing process (22nm vs 32nm)