[ramLlama]

Thing is, userspace networking is a lot like the GPU business. Often times, the software is free or even OSS, but the hardware is proprietary.

I know Intel has software for their NIC's to enable userpace networking, but I don't think any HFT uses it. It may be all right for hobbyist experimentation. I left the industry about a year ago, so my information is a bit out-of-date, but my former employer used either Solarflare cards with the OpenOnload stack (very good cards and awesome software) or the Mellanox CX series with VMA stack (amazing hardware with mediocre software. VMA is now open-source, so perhaps that situation has improved).

Note that these cards are a few thousand dollars each, so out-of-reach for hobbyists.

[lrizzo]

I can't comment on HFT because I have no experience on that, and their focus is latency rather than throughput.

For the latter (which matters in routers, for instance), netmap runs on everything (either natively or with some emulation). The intel 10g cards (which DPDK of course supports) are around 3-400$ i think, the 1G cards start around a few 10's of dollars (not that you need userspace networking at 1G).