Intel Xeon E3 1575M v5 's Advantages
Released 3 years and 10 months late
More modern manufacturing process (14nm vs 32nm)
Lower TDP (45W vs 130W)
Intel Xeon E5 1620 's Advantages
Higher specification of memory (DDR3 vs DDR3)
Higher base frequency (3.6GHz vs 3GHz)
Larger L3 cache size (10MB vs 8MB)