Win11, Z690, 13700k, 32GB DDR4, 2.5Gbit Realtek Ethernet NIC, Samsung 980 PRO NVMe.

I just installed Debian 12 on both VMWare Workstation (10.1.2.60) and VirtualBox (10.1.2.108), both using 4 “CPUs”, 4GB RAM, both using a bridged network to my one and only Realtek NIC. Everything else is default (even though I also tried with “vmxnet3” on VMWare, no difference). Running iperf3 on my Windows Host (10.1.2.15) and testing from both VMs produces these results.

I host my media server as a VM on VMWare and I don’t understand why Virtualbox is this much faster.

Hyper-V is disabled, Open-VM-Tools installed on Workstation VM.

If you could help me trying to figure out what’s appening or pointing me in the right direction to debug this I’d be grateful.