ASP.NET/mono performance on Linux

The best combination I have found, currently using in production, is fastcgi-mono-server2 or fastcgi-mono-server4 using nginx. A good alternative, that also is known to perform better than apache is, lighttpd.

I use Ubuntu Server 11.10 for my web servers due to very good package support (and updated) packages for the required components needed for the job.

You can found working configuration files examples for Demis Bellot here. He uses Centos.

I haven't tested it, but I would think it depends on what functions you're accessing in Mono. I wouldn't be surprised if the application would have to actually be tested with different web servers and configurations specific to the application in question to profile performance. There may be a particular function or behavior that can affect your profiled performance.