Intel Xeon E3 1558L v5 's Advantages
Released 4 years late
More modern manufacturing process (14nm vs 32nm)
Lower TDP (45W vs 95W)
Intel Xeon E5 4640 's Advantages
Higher specification of memory (DDR3 vs DDR3)
Higher base frequency (2.4GHz vs 1.9GHz)
Larger L3 cache size (20MB vs 8MB)