Mikrotik openvpn?

Question

Network administration

Good day. There is a server on Hetzner (grandfather)
KVM is deployed on it, including a router on MikrotikOS.
PPTP and OpenVpn are deployed on Mikrotik.
Direct exchange between the server and my PC is strictly according to my tariff, speed norms
Exchange via PPTP is slightly lower than the tariff, within the limits of encryption, etc.
Exchange via OpenVpn has become no more than 4-5 mb / s for some time now
KVM processor and at home it does not load even a third.
There is a similar server in Russia with about the same settings. Before it, OpenVPN with a normal speed, the tariff is minus 10%....
The question is whether the provider is to blame, or Hetzner? And how to check it?

Answer 1

In general, judging by the tests, it turns out that the speed is cut by KVM virtualization, apparently. The question still stands...