Help With External Monitor

[SIA Bouncer MW]

Just wondered if anyone could help me with a problem I'm having with an external monitor I've connected to my laptop using a mini display port to display port lead. The external monitor has this issue https://www.youtube.com/watch?v=wmkuso2iPX4
only when playing games. The problem doesn't occur when I disconnect the mains supply to my laptop and runs only off the battery. I already had an idea that it might be a "grounding loop" issue but it seems strange it only happens when games are running. Any help would be appreciated

Monitor is: Philips 272G5DYEB
Laptop is: Gigabyte P35 Geforce GTX970M I7-4720HQ 16GB RAM

 

[regularcat]

It is most likely a shitty adapter causing the problem.

What type of adapter is it, VGA to VGA, HDMI to Mini HDMI ?

 

[bangus]

If it runs fine off the battery, I would guess the issue is with your power plan options, they may need adjusting: start menu / control panel / hardware sound / power options.
And of course you're aware of the multiple display setting so I won't even mention that one.

 

[SIA Bouncer MW]

It is most likely a shitty adapter causing the problem.

What type of adapter is it, VGA to VGA, HDMI to Mini HDMI ?

Mini display port to display port, yeah I did think that myself.

 

[SIA Bouncer MW]

If it runs fine off the battery, I would guess the issue is with your power plan options, they may need adjusting: start menu / control panel / hardware sound / power options.
And of course you're aware of the multiple display setting so I won't even mention that one.

Cheers, I'll have a fiddle with those options again