Intel Xeon W3690 's Advantages
Higher base frequency (3.466GHz vs 2.2GHz)
Larger L3 cache size (12MB vs 1.5MB)
Intel Xeon D 1531 's Advantages
Released 4 years and 9 months late
Higher specification of memory (4 vs 3)
Newer PCIe version (3 vs 2)
More modern manufacturing process (14nm vs 32nm)
Lower TDP (35W vs 130W)