Intel Xeon E5 2420 's Advantages
Released 2 years and 9 months late
Larger L3 cache size (15MB vs 8MB)
More modern manufacturing process (32nm vs 45nm)
Lower TDP (95W vs 130W)
Xeon W5590 's Advantages
Higher specification of memory (1333 vs 3)
Higher base frequency (3.333GHz vs 1.9GHz)