Xeon L5639 's Advantages
Released 11 months late
Higher specification of memory (1333 vs 3)
Larger L3 cache size (12MB vs 4MB)
More modern manufacturing process (32nm vs 45nm)
Lower TDP (60W vs 80W)
Intel Xeon E5507 's Advantages
Higher base frequency (2.266GHz vs 2.133GHz)