Intel Xeon E3 1275 v5 's Advantages
Released 5 years and 7 months late
Newer PCIe version (3 vs 2)
Higher base frequency (3.6GHz vs 2GHz)
Larger L3 cache size (8MB vs 4MB)
More modern manufacturing process (14nm vs 45nm)
Intel Xeon E5503 's Advantages
Higher specification of memory (DDR3 vs DDR3)