Hi, we've encountered a weird performance issue in a tx only scenario: The performance drops by about 30% to 40% with the following configuration.
* i7 or Xeon E3 CPU * Linux kernel 3.16 or later (tested 3.16, 3.19, and 4.4) * ixgbe-based NIC The problem goes away if I either use an Xeon E5, an older Linux kernel (tested 3.13 and 3.7), or an i40e-based NIC. I suspect that this is related to DDIO since a "proper" server CPU solves the problem. Any ideas how to mitigate this? This issue currently keeps us from upgrading the OS of an old Ubuntu 14.04.01-based machine. Paul
