10GbE Tweaking Details

The following tweaks can increase 10GbE throughput by up to 200 MB/s. First the adjustments on Intel's X540-T1 NIC. If you have a -T2 NIC and are using both channels, be sure to make the changes on both sets of properties.

First, set jumbo packets (frames) to the maximum 9014 Bytes.

Intel X540 NIC tweak - jumbo frame

Then set Receive Side Scaling (RSS) queues to match the CPU logical core count. On an i7 based computer with hyper-threading enabled (you may have to turn this on via computer’s BIOS), you should see 8 cores.

Intel X540 NIC tweak - RSS queues

And make sure RSS is enabled.

Intel X540 NIC tweak - RSS enable

Next, disable Virtual Machine Queues if you see this option (Server 2012 only).

Intel X540 NIC tweak - Virtualization

Then increase receive buffers to the maximum (4096).

Intel X540 NIC tweak - RCV buffers

And also increase transmit buffers. Their maximum is 16384.

Intel X540 NIC tweak - XMIT buffers

Once you have made these changes, you should see some impressive speeds. Remember to create and share RAM disks on both your target and host machines while testing, to eliminate disk speed limitations.

Conclusion

As a teaser, your 10GbE workstation will also work quite nicely as a 4K player just in case you have a 4K display handy. For many of you, just purchasing a 10GbE enabled NAS unit is all you’ll need for a server. Just remember to enable jumbo frames and check that SMB3 is enabled! On QNAP’s lastest firmware, you’ll find those settings here:

QNAP Jumbo Frame setting

And here:

QNAP SMB3 enable

In the next installment of this series, I’ll show you how to build a Windows 8.1 video editing workstation and Windows 2012 shared storage server affordably capable of maxing out a 10GbE connection.

Dennis Wood is Cinevate’s CEO, CTO, as well as Chief Cook and Bottle Washer. When not designing products, he’s likely napping quietly in the LAN closet.