I use nginx to serve the static content for a decently busy website of mine. I have the logging disabled, and 4 worker processes enabled with 5,000 connections per worker (which should yield a max connection limit of 20,000.

The server is only operating at about 10% CPU usage and 50% ram, but it's very laggy, and sometimes nginx is so slow to respond to the requests, it times out. For a small number of connections, it's fine, but once any load starts occurring (~2,500 connections), it backs up and bogs down.

Is there any other bottlenecks or limits that I might be hitting? This is a FreeBSD server, and all the static files are located locally (not NFS). The NIC is an unmetered gigabit, and it's only using around 75 megabit.

Any insight would be appreciated. Thanks.