Less than 10 fps in fullscreen with a second monitor plugged in

Rowan Scott

Reputable
Nov 20, 2014
16
0
4,510
I recently started re-using an old monitor as a second monitor for watching videos or monitoring performance while playing games on the main monitor but when the old monitor is connected games I run in fullscreen will drop to an un-playable framerate I first thought it was the game I was playing but it did this with any game I played, FPS is absolutely fine when playing in windowed of borderless window.

Does anyone know what may be causing this?!

Specs:
Main monitor: BenQ XL2420G
Second monitor: Dell monitor at 1024p 75Hz
CPU - i5-3570K Turbo boosted @ 3.9GHz with stock cooler
GPU - GeForce GTX 980
PSU - Antec TP classic 650W
HDD(s) - WD blue 250Gb and a 1T
RAM - Corsiar vengeance 16GBs @ 1600MHz
OS - Windows 10

EDIT: "I'm a moron and it turns out it was most likely because the cable was in loose somehow even though it was screwed in on both ends, works fine now."
 

Rowan Scott

Reputable
Nov 20, 2014
16
0
4,510


Temperatures has nothing to do with it, I've already checked that and I don't get low fps in fullscreen if I disconnect the second monitor