Trouble with multiple displays not at their max refresh rate

[MrReptilian]

So i just bought a new 1440p 144Hz ASUS monitor, and so far it's been great, along with my RX580 i can play DOOM 2016 at like 120fps and such.

 

The problem arises when i setup my old (1080p 60Hz) alongside the new one, and since then, the new monitor is stuck at 100Hz, even if i change it to 144Hz if i leave the menu it just goes back to 100Hz. Now, after disconnecting my old monitor, i can use 144Hz no problem, so my question is, is my GPU too weak to handle both at their "max"? what card would be able to?

 

New monitor: ASUS TUF Gaming VG27WQ1B

Old monitor: Samsung T24C301

GPU: Sapphire RX580 4GB

[mr cheese]

are you using them through DP or HDMI?

[MrReptilian]

52 minutes ago, DaJakerBoss said:

are you using them through DP or HDMI?

DP for the new 1440p one, HDMI for the old 1080p one (the old one only has 1 HDMI port)

[KeyLimePrime]

I'm being shipped a 144hz monitor, and I was concerned about this sort of thing occurring as well. I'm very reliant on my second monitor for messaging/browsers even when I have a game up, or having a video run in the background.