VirtIO drivers are all that you need to setup on the Proxmox VE guest to see the best performance inside the guest, if it is a Windows guest you additionally need to install drivers.
I would suggest to perform network benchmarks with iperf:
- Whether the Proxmox VE host can actually reach 10G speeds. You can perform this test between the host and the closest thing to it, e.g. the network switch, or test it directly against another host which you know can reach that speed.
- Test the network speed between the guest VM and the host