Make sure MSI-X is enabled in the BIOS(which hopefully is fully updated), then use this article to turn on RSS:
Also look to make sure your linking at the right speed, not get a ton of collisions, retransmissions, drop packets, or other TCP type errors.
If that doesn't help out, look for my blog on performance next week. And if that doesn't help let me know
I appreciate you using Intel(R) Networking and I hope we can get the performance up for you.