If you want 40M connections, on FreeBSD, the maxfd count is physpages / 4; you could edit the kernel to change this, but are you really going to serve 40M conne

If you want 40M connections, on FreeBSD, the maxfd count is physpages / 4; you could edit the kernel to change this, but are you really going to serve 40M connections with only 16k ram for each user? If my math is right that puts you around 640GB of ram. (40M * 4096 * 4 = 40G * 4 * 4 = 640 G), which is totally doable on a server socket. Probably you don't have everyone simultaneously connected, but probably you also need more ram per connection, so kind of depends. By the time you find 40M users to connect to your server, you should be in tune with your hardware needs ;)