[SOLVED] PC fps tanks when fullscreen

rileyallan

Honorable
Oct 1, 2015
19
0
10,510
When I try to watch videos on VLC/Windows Media Player/Ace player and when I play League of Legends my FPS plummets when I fullscreen the apps. But when I window the videos/game the fps comes back. Games such as Mirror's Edge, Call of Duty and CSGO work fine fullscreened.

Occasionally it also happens on firefox and the fps drops to 15-25 when watching youtube/twitch.

Tried a malware scan but found nothing..

My RX 5700XT has been a nightmare with awful drivers causing blue screens and stuttering forcing me to use older drivers from 2019 but since version 20.3+ those issues went away.

Imgur link -

View: https://imgur.com/a/ywbkPlj 1 : fps counter [top right] with league windowed, constant 200fps 2 : league fps during fullscreen, between 15-25 3 : task manager when fullscreened on league

Could some windows settings/radeon software settings be the problem? Should I reinstall a fresh windows?

Specs below :

CPU - Ryzen 5 3600
Mobo - MSI B450 GAMING PRO CARBON AC ATX AM4
RAM - Corsair Vengeance RGB Pro 16 GB (2 x 8 GB) DDR4-3200 CL16 Memory
Storage - Intel 660p Series 1.02 TB M.2-2280 NVME Solid State Drive
GPU - PowerColor Radeon RX 5700 XT 8 GB Red Devil (Up to date drivers) 20.4.2/20.5.1
PSU - Corsair RM (2019) 650 W 80+ Gold Certified Fully Modular ATX Power Supply
Display - Dell S2719DGF 27.0" 2560x1440 155 Hz using DP 1.2