Help with connecting and Xbox 360 E to a gaming monitor

I've recently just dug out my old 360 and I'm trying to connect it to my BenQ XL2340T gaming monitor which is natively 1920x1080 and I'm struggling with the resolution. I've enabled 1080p in the settings but it looked particularly grainy and blurry, something you'd expect from a lower resolution, and so I tried 720p which looked identical with no drop in quality from the supposed 1080p setting. I've fiddled around with the monitor settings too which came to no avail. Can anybody help with this?

Submitted by sampickeringg | #Specialdealer Special Offer Online Shopping Store 2016