updated 12:48 pm EDT, Tue August 12, 2014
Speeds up interface, apps
NewerTech had released an accessory for the Mac mini, the Headless Mac Video Accelerator. Although Minis are often used as headless servers, the computer will automatically disable its GPU when a monitor isn't detected. This can potentially cripple performance in some tasks, such as accessing a Mini remotely, which is often necessary when it's in server mode.
The HMVA is a display adapter that fools a Mini into thinking a monitor is attached. This forces it to load video drivers, and hence both the OS X interface and any graphics-intensive apps should run at normal speed. NewerTech is selling the accessory for $19.