network speed problems

[toto-ets]

Hi everyone, I'm explaining my problem. I have 3 nodes with Proxmox 9, and each node has 10G network cards.
Doing some testing, I noticed from various complaints from my customers that VM traffic can't exceed 3G, either between VMs, even on the same node, or between VMs and the outside world. However, when I do traffic tests between the various nodes (such as Ceph traffic, migrations, etc.), traffic between the nodes easily reaches 10G. Could someone tell me what I could check or how to configure the VMs to get the best performance on the network? I'm also wondering why, even if I put 2 VMs on the same node, the traffic between them is always terrible?

 

[_gabriel]

2 VMs on the same node, the traffic between them is always terrible

it's bounded to cpu as flow is done over virtual switch / software bridge.

 

[toto-ets]

and when I go outside? , then the strange thing is that in download on the VMs if I do a spidtest I go at 4G, in UP I go at a full 10G What should I do to solve this problem? Instead if I do it between the VMs and VMs I go 4G down and 4G an UP

 

[_gabriel]

you need to test speed between your nodes before test upstream connection.
what about iperf test from VM of node1 to VM of node2 ? VM node1 to node2 ?

 

[toto-ets]

I have already done this test and it gives me 4G from the VM of node 1 to the VM of node 2, and 4G from the VM of node 2 to the VM of node 1, if instead I do a test from the VM to the router I get 4G in down and 10G in UP, this means that all the VMs have down of 4G and UP of 10G, if instead I do the test from one node to another I get 10 down and 10 UP, and it is as if all the VMs have down up to approximately 4G