Intel Xeon E3 1258L v4 's Advantages
Released 3 years and 3 months late
More modern manufacturing process (14nm vs 32nm)
Lower TDP (47W vs 130W)
Intel Xeon E5 1660 's Advantages
Higher base frequency (3.3GHz vs 1.8GHz)
Larger L3 cache size (15MB vs 6MB)