Hello!
If you use KVM virusization, if you don’t get a suitable network speed (for example, 100 Mbit / s, when you should get 2 times more), you can try the following

open /etc/sysctl.conf on your server and add the following with

net.core.rmem_max=16777216
net.core.wmem_max=16777216
net.ipv4.tcp_rmem=4096 87380 16777216                                          
net.ipv4.tcp_wmem=4096 65536 16777216

Now in the terminal run the following command:

sysctl -p

Next, check the speed again. This should to help you!