(Tailscale cofounder) I see a few comments here that using kernel wireguard would make it faster; it’s not really that simple. In fact, for a while (and we wrote a blog post about it), our optimizations made wireguard-go faster than kernel wireguard because it was better optimized. They adopted some of those improvements and now we’re on to the next order of magnitude together.

For really high bandwidth cases, things like DPDK are the long term best choice and are primarily userspace, for good reasons. Kernel mode is not the pure benefit it once was (if it ever was).

Separately, wireguard itself has a problem that the crypto suite it uses is not supported by hardware accelerators. So if we want to get into the hundreds of gigabits range, we will possibly need to switch packet formats entirely. (But, wireguard also needs to update to support post-quantum so maybe they’ll fix both problems at the same time and we can join in.)