Why Skylake CPUs Are Sometimes 50% Slower
2 elements are fuzzy:
- clock speed is way different from 3.5GHz to 2.6. This can lead to huge differences in some computations and no new instruction set can compete against brute force. 
- changing between those 2 cpus is not just a socket swap but a full platform change: can we get the other details of the 2 platforms ?