Thanks for sharing. I'm happy to see that this topic is getting traction and I'm not the only one affected by it. I wonder on how many NICs RSS isn't actually working and how this could have gone unnoticed for so long.
I would like to ask anybody that reads this and has a Intel NIC installed that is supposed to have RSS enabled (check the advanced driver settings of the NIC in question for that option) and perform the mentioned PowerShell commands.
Quick methodology to check RSS under Windows 8.x in four easy steps:
1) Launch PowerShell as Administrator
2) get-NetAdapterRSS - If RSS is enabled in the NIC's driver there is going to be a line with "Enabled" and "True" however the property "IndirectionTable" must not be empty (this it is on all NICs where RSS is not working)
3) get-SMBClientNetworkInterface - check if Windows considers the NIC RSS capable when receiving data
4) get-SMBServerNetworkInterface - check if Windows considers the NIC RSS capable when sending data