Intel Xeon E5 1660 's Advantages
Larger L3 cache size (15MB vs 8MB)
Intel Xeon E3 1285 v6 's Advantages
Released 5 years and 5 months late
Higher specification of memory (DDR4 vs DDR3)
Higher base frequency (4.1GHz vs 3.3GHz)
More modern manufacturing process (14nm vs 32nm)
Lower TDP (79W vs 130W)