Gen8 NIC - missing buffer setting

I have a dl360p Gen8 server with the stock 331FLR adapter, running Windows Server 2008 R2. On older generations of servers/NICs, we changed a NIC setting called "Receive Buffers". This setting was available either in the NCU, or in the adapter settings on the Advanced tab.

On the Gen8 the setting is entirely gone - but it's pretty critical that we be able to change it. Any idea how I can access and change that setting?

Thanks,

Eric