High Performance Tuning

First, make sure you're following Best Practices.

Tune Disk/Memory:
If you have plenty of RAM, disable swap altogether.

Use hdparm to gather drive statistics and alter settings, as described here:
http://www.linux-magazine.com/Online/Features/Tune-Your-Hard-Disk-with-hdparm

vm.dirty_ratio is the maximum amount of system memory that can be filled with dirty pages before everything must get committed to disk.

vm.dirty_background_ratio is the percentage of system memory that can be filled with “dirty” pages, or memory pages that still need to be written to disk -- before the pdflush/flush/kdmflush background processes kick in to write it to disk.

More information: https://lonesysadmin.net/2013/12/22/better-linux-disk-caching-performance-vm-dirty_ratio/

Disable GUI:
http://askubuntu.com/questions/16371/how-do-i-disable-x-at-boot-time-so-that-the-system-boots-in-text-mode

Disable Bluetooth:

sudo systemctl stop bluetooth.service
sudo systemctl disable bluetooth.service

Other
Consider adopting some of the suggestions from here:
https://github.com/pevma/SEPTun https://github.com/pevma/SEPTun-Mark-II