TTFB - Very long delay

Hello!

I’m trying to get to the bottom of my TTFB issues. I’m having a pretty long delay for my Vanilla Forums page somewhere around 1.5s and strangely as high as 4s.

I’m running nginx, php-fpm, php-apc. I’m utilizing memcached for php content and I’m operating a MariaSQL database with a unix socket for communication.

I’ve got a KVM VPS with 2x3.3GHz, 512MB Ram, 1024MB swap. I took these pictures before I upgraded from a 1x3.3GHz 256MB, 256MB swap VPS. Imgur: The magic of the Internet

I tried to use mtr to see if there was any appreciable packet loss, and there wasn’t. Excellent connectivity. Disk IO, as you can see, is also pretty decent.

I’m quite new to webhosting, so I possibly configured something incorrectly?