Virtual Machine Device Queues (VMDQ) Reduced to 64 after PROSet Driver Update

When using the default Windows* driver for two X520-T2 Network Interface Controllers (NICs), the maximum VMDQs available are 126. After updating the PROSet driver to version 25.4, the VMDQs are reduced to 64.

The reduction in queues is caused by an optimization that is applied to the Intel PROSet driver, but not to the inbox driver (via Windows update).
This can be modified by changing a registry key: NumRssQueuesPerVPort
The default setting of this registry key causes queues to be pooled in groups of 4 to boost performance for non-default vPorts.

• A non-default vPort is an internal port that is attached to a virtual function.
• A default vPort is attached to a physical function.

By reducing the value of this registry key to 2 a total 126 of VMDQs can be created.

How to add, modify, or delete registry subkeys and values by using a .reg file