Intel Xeon E5 1603 v3 's Advantages
Released 2 years and 6 months late
Higher specification of memory (1866 vs 3)
More modern manufacturing process (22nm vs 32nm)
Intel Xeon E5 1660 's Advantages
Higher base frequency (3.3GHz vs 2.8GHz)
Larger L3 cache size (15MB vs 10MB)
Lower TDP (130W vs 140W)