Optimizing Windows Server NIC Cards

Here we had a high traffic server that was constantly having network related issues at the NIC level so I sought out to investigate what all these different configurations mean in the advanced tab for the adapter properties. For this example I'll be looking into HPNC373i but the exact available settings differ from one manufacture to another. First things first and I can't stress this enough, make sure you have the most up to date firmware and drivers from the manufacture's website. That in itself can make a world of difference. I'll be going through about the recommended settings for: - Ethernet Wire Speed - Receive Side Scaling - Flow Control - Speed & Duplex - Transmit Buffers - Receive Buffers - 802.1p 802.1p can remain disabled. What that does is mark packets for QOS purposes so that other intelligent upstream devices will prioritize traffic. In a standard Ethernet cable there are 4 pairs of wires (8 conductors). With 1000BaseT adapters as little as 2 of those pairs are used in the initial power up sequence to negotiate the data speed for the connection. This can result in problems so Ethernet Wirespeed enables the adapter to establish a connection at a slower speed (This is a Broadcom chipset specific driver). I recommend disabling this as it causes problems sometimes, speed issues mainly. Flow Control should be disabled. What it does is moderate the flow of traffic in networks mixed of Gb and Mb traffic. Usually does more harm than good since most of that stuff already exists already in the TCP stack. Receive Buffers should be set as high as possible. This specifies how much memory is allocated to the NIC card for processing. One thing to note is that servers with low memory this may be better left to auto. The buffers are taken from the server physical memory. Transmit Buffers similar to receive buffers is related to how many packets the NIC can have in its queue. Always have this set to the highest. Transmit buffers all come from physical server memory. Speed should be set to the maximum setting that your switch can support and Duplex should be set to FULL. You will then need to also go back and configure the switch or router that the server is connected to with the same configuration. Receive side scaling should be used if the server has multiple cores and is not hyper threaded. RSS offloads the NIC process work to each core of the server instead of just one. This is useful for great spreading of CPU load. I would also recommend at this time to remove any unnecessary network protocols and make sure that the bindings are ordered correctly according to your network needs.You should also make sure your primary network connection is first priority. You can find the binding and priority order by right clicking Network Connections > Click Properties> Click Advanced > Then choose advanced settings. From there you can change the order for example moving file and print sharing to the top and moving your primary network connection to the top.

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