VMXnet3 Server 2025 performance issues

Copper Contributor

Had an odd one crop up today.  I updated my Server 2025 template to the 26063.1 release and then sysprepped it.  Converted it back to a new VM and network performance was .25 Mbps down.  Both on my local lan and on the internet.


I removed the VMXnet3 and put in an E1000 and performance was exactly as expected.


I shut the VM down, removed the E1000 put in a new network with vmxnet3 and again got horrible performance.


I have not seen this with other deployments of 2025 earlier builds.

3 Replies


Could you provide further information about your setup? For example, which version of ESXi are you using? Also, what is the version of the vmxnet3 driver?how many vCPU you allocated to your VM?


@Jeff_Riechers Delete your ghost NIC and your vmxnet driver. When you add the new NIC it'll poll for the actual VMware tools driver vs what it thinks works. Sysprep seems to do this in 2019+ sometimes if you don't have the drivers manually added to drivers and just VMware tools. E1000 will always work.

Hi Jeff
Do you still see the problem reproduced with 26080 build?