I bought a new monitor and connected it to my video card via HDMI. The video output was shrunken, with ~1″ black borders all around the screen. At first I thought the monitor was defective but I tested using a DVI cable and the display was fine. Much googling later, I figured out it’s an issue with ATI/AMD’s catalyst control center. Basically you have to set overscan to 0% in the catalyst control center to rid yourself of this issue, something that’s not at all intuitive – even finding where to change that setting is a chore. This post on aoclarkejr.com was super helpful and has pictures of each step you need to take. I found that via this forum thread. Posting this just in case it helps others solve this issue.