Intel Xeon D 1581 's Advantages
Released 5 years and 11 months late
Higher specification of memory (4 vs 3)
Newer PCIe version (3 vs 2)
More modern manufacturing process (14nm vs 32nm)
Lower TDP (65W vs 95W)
Intel Xeon X5650 's Advantages
Higher base frequency (2.666GHz vs 1.8GHz)
Larger L3 cache size (12MB vs 1.5MB)