Intel Xeon E5-2643 v4 vs Intel Xeon E5-2690 v4: What is the difference?
Rendering Performance - Intel's Xeon E5-2600 V2: 12-core Ivy Bridge EP for Servers
CPU-Z Benchmarks on various Synology models - Hope this helps give a rough idea of the CPU power difference between models. Also included 2 other VMs running on Windows Hyper-V Server. :
Intel Xeon E5-2690 review | 56 facts and highlights
Xeon E5-2690 V2 vs Celeron M 340 PassMark Single Thread Mark パフォーマンス - CPUAgent
CPU Benchmarks - Intel Haswell-EP Xeon 12 Core Review: E5-2650L V3 and E5- 2690 V3