Intel Xeon E3 1220 's Advantages
Higher base frequency (3.1GHz vs 1.8GHz)
Lower TDP (80W vs 225W)
Xeon 6756E 's Advantages
Released 13 years and 2 months late
Higher specification of memory (6400 vs 3)
Newer PCIe version (5 vs 3)
Larger L3 cache size (96MB vs 8MB)
More modern manufacturing process (5nm vs 32nm)