Intel Xeon E3-1220 v3 vs Intel Xeon E5-1603 v4: What is the difference?
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 E3-1220 V3 UnixBench Multi Threaded - ServeTheHome