R9 280 3 Monitors only 60Hz (2x 120Hz, 1x 60Hz)

[Blackbone]

I've 3 Monitors, 2 over DVI-D and one over active displayport to hdmi cable. When i only use my 2 120Hz monitors, i get actually 120Hz but when i want to activate all 3 Monitors for windows, i need to set every monitor to 60Hz.

Is this a problem by the GPU?
Does a Nvidia GPU work with 2x 120Hz and 1x 60Hz?
Anybody any idea?

 

[Guest]

R9 280 doesn't support HDMI 2.0 which means that whatever is plugged into your HDMI port on your graphics card will not go above 60hz, regardless of any converters you use.

Why you can't have 2 of them in 120hz and 1 in 60hz, I don't know. I'll let someone else attempt to answer that.

 

[Blackbone]

R9 280 doesn't support HDMI 2.0 which means that whatever is plugged into your HDMI port on your graphics card will not go above 60hz, regardless of any converters you use.

Why you can't have 2 of them in 120hz and 1 in 60hz, I don't know. I'll let someone else attempt to answer that.

The displayport - hdmi adapter is only used with my 60Hz monitor. I restarted my computer and disabled the 3rd monitor in windows and it turns out that i can't select anyting else then 60Hz if i have 3 Monitors connected.