Getting Major Screen Tearing in Portal!?

[Johnmakuta]

I've just started playing portal (I'm cheap and got it on a steam sale) and I'm getting major screen tearing when moving my mouse around. I am playing on an older Asus ROG laptop with a GTX 965m inside it but I feel that should be powerful enough to run portal at 1080p! Is this something that would be fixed by a G-sync monitor? Or just moving back to my desktop with a better graphics card? I have had screen tearing happen before in other games on this laptop so it could be that the screen is just getting old. Please help!

[GreezyJeezy]

cap that FPS fam 

[Squirrel724]

Use VSync to cap your FPS to the refresh rate of your monitor. Portal is so easy to run that you are probably getting between 200 and 400 fps. If it is not running at a multiple of the refresh rate of the monitor the GPU is rendering the frames at a different rate to how the monitor is displaying them. This means that sometimes when the monitor goes to display a new frame it gets an image from the GPU that is half a new frame and half an old frame. This creates the tearing that you see. By capping the fps to the refresh rate of the monitor (or a multiple of that refresh rate) you ensure that the monitor always gets a complete new image, preventing tearing. 

Basically your issue is too much power instead of too little power. Turning on VSync or using an external application to limit your frame rate will get rid of the tearing.