S3221QS, 2012 MacBook Pro, screen distorted

Hi all,

I recently purchased this monitor to use with my 2012 MacBook Pro. Using the monitor HDMI to HDMI, I am only able to achieve 4K at 30Hz. This is a little slow/ glitchy. To get 4K at 60hz, I bought a cable mDP/Thunderbolt to DP cable to use for the monitor. Unfortunately, when I connect it to the monitor, this is the image I get (pasted below) 

The HDMI to HDMI work fine, just a bit slow. The graphics card on my MacBook works fine. I have tried 2 different mDP to DP cables, both have the same issue. Any suggestions on what the issue is?

Thanks in advance