is my graphics card dying or its monitor?

[Modestas_2]

Hello, just strange thing happend. Was playing overwatch and suddently my computer start going crazy, fps was droping from 150 - to 5 in random numbers. Restared my computer and now in my monitor corner is this white lines. even when i open any games theyr are still here.but i did screenshot and there is no lines.
everything you can see is in picture.

GPU geforce 750TI
Monitor is 4months old asus VG278HV 144hz

 

[dontlistentome]

Does your computer have some kind of integrated graphics? If so, switch to the integrated graphics and see how things look. If everything looks fine, it means the videocard is the problem. Otherwise it's the monitor.

If you're gaming at 150fps constantly, you might have damaged the videocard depending on what kind of temps it hit. Most 750 Tis aren't really geared for that kind of high fps performance. They were entry level gaming cards, where hitting 60fps would have been considered best case performance.