1440. 1440p

Hi, I have recently bought a new monitor at 1440p and 144hz. I am currently using a HDMI to usb-c cable to connect to my MacBook Pro 2019 and have the refresh rate set to 144hz but it doesn't seem to be running very smooth... there seems to be a little bit of screen lag going on, definitely...

I have a HIS r9 290x and having some massive issues with it, it runs 100% gpu load idle, green artifacts, crashing black screens. Fresh windows installed. I checked the load from gpu-z and msi afterburner. Temps are stable 50-60c idle. NO malware or virus or even any weird apps running in task...