Intel Xeon E7 8870 's Advantages
Larger L3 cache size (30MB vs 22.5MB)
Lower TDP (130W vs 165W)
Intel Xeon Gold 5515 's Advantages
Released 12 years and 8 months late
Higher specification of memory (DDR5-4800 vs DDR3)
Higher base frequency (3.2GHz vs 2.4GHz)
More modern manufacturing process (10nm vs 32nm)