Why does SSD speed in Proxmox sag compared to bare-metal?

Question

Solid State Drives

CrystalDiskMark on the installed Win server 2016 - shows results close to those declared by the SSD manufacturer.
If you run Proxmox and install Win Server there, then CrystalDiskMark shows the results an order of magnitude lower. For example, in bare-metal, the random write speed is 35, and in a virtual machine, 1.5.
I tried to change the type of VM disk in the settings (SAS, SATA, Virtio SCSI), cache enabled / disabled. The test results do not change.

Answer 1

Are the drivers inside the Windows guest virtual machine installed?
Have you set up paravirtualization modes?
https://pve.proxmox.com/wiki/Windows_VirtIO_Drivers

Answer 2

And storage not Ceph a case? I just now installed a virtual machine on RBD on Ceph on NVME, and the write speed in the sysbench test turned out to be 15MiB / s versus 262MiB / s on bare metal. This is one and a half times higher than on bare metal cephfs, but still sad.
And the pool on NVME gives a slightly lower speed than on SSD - generally strange.