If onboard and dedicated graphics used, is there priority for onboard card?

[Astralv]

I am connecting Hesswell computer with Asus Z87 Deluxe motherboard to 2x 4K monitors. I have one display port on AMD Radeon 7870 card and one display port on motherboard graphics. For some reason, the Main monitor (where the desktop icons are) only can be assigned to the monitor connected to the On Motherboard graphics. If I have desktop set to AMD card, it does not light up the monitor. Other words- monitor connected to On Motherboard graphics does not work in extended mode, only works if set to be a desktop. I wanted my main monitor (the one I read from) to be connected to AMD as it supposed to be better graphic, but it would not work unless the desktop in on Motherboard graphics- it is the only way to light up 2 monitors. Any explanation? Thank you.

 

[RobCrezz]

You should be able to do that. Just set the primary monitor to the one plugged into the 7870, then tell it to extend the desktop to the monitor on the intel cpu.

I do exactly this on my 1060 and 2500k.

 

[Astralv]

You should be able to do that. Just set the primary monitor to the one plugged into the 7870, then tell it to extend the desktop to the monitor on the intel cpu.

I do exactly this on my 1060 and 2500k.

Thank you for your reply. I used to have 4k monitor and 2500 resolution (2K) monitor and I had my desktop on 4K, but now that I am thinking- I did not pay attention to what port was connected to what (I have KVM switch in between).

But now with 2x 4K monitors, it does not work. When I have main monitor connected to AMD card set to be Desktop, only one monitor works. The 2nd monitor shows small icon, when selected, the options either grayed out and if I set it to extended mode, it goes right back to "Show desktop only on 1", or it shows everything normal but no light on 2nd monitor. To make 2nd monitor work, I have to unplud cable from AMD, let it detect On Motherboard graphics, boot one monitor, then connect cable from AMD graphics.

If I try the same thing from AMD, I think- I get AMD monitor to work as a desktom and On Motherboard connected monitor never comes on.

 

[RobCrezz]

Oh right, yeah go into your bios, you need to enable multi monitor (or might be called something else), so the iGPU is still enabled when you run the graphics card as the primary.

 

[Astralv]

Yeah, I know. It is enabled.

I do get 2 monitors, but only if On Motherboard connected monitor is Desktop.

I dont think KVM switch would have any preferences for what is connected to what- should be identical ports...

 

[RobCrezz]

That is odd, shouldnt be the case. Might be worth trying without the KVM switch in case its interfering.

 

[Astralv]

And today it working. Strange, but I will take it. Thank you.