Xeon W 1390's Advantages
Released 6 years and 8 months late
Higher specification of memory (DDR4-3200 vs DDR4-1866)
Newer PCIe version (4 vs 3)
Larger L3 cache size (16MB vs 10MB)
More modern manufacturing process (14nm vs 22nm)
Lower TDP (80W vs 105W)
Intel Xeon E5 2623 v3's Advantages
Higher base frequency (3GHz vs 2.8GHz)