I figured it out. Turns out I had a gen 1 crappy Displayport to Displayport Mini cable. (Insignia by Best Buy, go figure) I bought a new one and made the switch. 144hz works just fine now.
Windows Version 8.1
Monitor: ASUS VG248QE (rated up to 1920x1080, 144hz)
Monitor Ports: HDMI v1.4 x 1, DisplayPort v1.2 x 1, DVI (Dual-Link) x 1
Graphics Card: Nvidia Geforce 970M (Laptop. Drivers are current)
Ports: VGA, HDMI, DisplayPort Mini
I am aware of this monitor's inability to...