When i play games in fullscreen i get white horizontal lines flashing on the screen about every 30 seconds, i also get them in the game menu, tested on two monitors over VGA and HDMI. It happens at different resolution and different refresh rates. It doesn't happen when i play games in fullscreen-borderless and in windowed mode, only happens in fullscreen. I removed the drivers and installed a different version but it doesn't solve the problem. It happens more often when i have unlocked fps, the gpu is always under 50C. I think it's the gpu, what do you think? If that's the case i will upgrade in a few months. I have an i7 4770k overclocked at 4.4Ghz, r9 380 non OC, 8gb 1600mhz ram.