Hi !
The tests posted above (in the first post) were made directly on host running Windows 2012 R2 Standard (Hyper-V root partition).
The performance diference inside VM (Hyper-V child partition) is even worse, but only when reading/writing small blocks (attached picture). This is the benchmark from the VM that i mentioned in the post from Dec.2. It is running on the R2200 (gen2, 4cpu, 4gb ram, fixed size scsi vhdx):
As you can see, the performance in this VM shows more nonlinearity if compared to Hyper-V root partition (first post, first picture). Small blocks reads and writes are (in my opinion at least) much slower than expected..