You will often see “runs on commodity hardware” on a SDN product website. What does it really mean?
Sometimes when Router Analysis gets a new piece of SDN software to test the results come out much better or worse than what the vendor claims. The most recent occurrence of lower performance happened as we started testing Vyatta’s R6.5 in our lab.
When testing you need to have an initial benchmark that you can use to tell you what effect features and other changes you make to the system configuration have. For Vyatta we took a simple approach. Fire up the LiveCD image and run traffic across 2 GbE ports.
Router Analysis previously interviewed Vyatta spokesman Scott Sneddon and found out that the performance of a Vyatta system could be as high as 2Mpps (2 Million packets per second) at 64 bytes. Our first run produced 1.78Mpps. After a short Twitter discussion, it was determined that the number was expected with the hardware we are using (Intel i7-3770 CPU, 32G ram, Intel c216 chipset and Intel Ethernet Interface cards).
We decided to do a little testing to see what the bottleneck was and how we could reduce it. As we debugged the issues and changed the hardware setup we got the Vyatta system up to 2Mpps. Adding in another pair of ports and doing more tweaking we got to 2.9Mpps then early this morning 3.6Mpps. 3.6Mpps is a really good number for a software based forwarding router. To compare, the Cisco 7200 VXR with a NPE-G2 can do 2Mpps and the 7200 VXR is a very specifically designed system with a proprietary OS designed for one thing, routing.
Besting the Cisco 7200 with PC hardware is pretty good, but doing it with PC hardware that is forwarding at almost 2x the pps and at the time of this writing 4x the bandwidth (we have tested up to 6Gbps on the Vyatta, the 7200 supports 1.8) is impressive.
Cost wise, the test system we are using is not that expensive. Custom built for us by IXSystems the system is based on a Supermicro motherboard with the Intel c216 chipset, a QuadCore Intel i7-3770 CPU and 6 PCie slots. Since we outfit the machines with 32GB of ECC ram, it is easy to take the difference in memory cost and apply it towards the necessary network cards. Fully configured the system would come out well below $2000 US (or less if you source the NICs on the used market).
What is commodity hardware? It’s still new hardware and it’s still good quality. If you want to just throw together something from parts you find around the office, you can. But if you intend to have a reliable and functional system, you need to do the hardware design properly.