I bought two VG280K monitors, but I'm unable to run both at 3840x2160 @ 60Hz

darrel

I can run one at 3840x2160 @ 60Hz, but when I try to run the other at that, too, the screen goes black.  If I set it to run at 3840x2160 @ 30Hz, then it works.  Why can't I run them both at 60Hz?  Is this a limitation with the monitors or my video card?  Nvidia GeForce GTX 1660 SUPER with 6GB RAM, which seems like it should be able to do this just fine.

billsey

No limitation with the monitors themselves, they just do what the GPU says. So it's a limitation of your GPU or computer. What ports are you using on the 1660?

darrel

Thanks, billsey.  I think the issue might be with a display switch was using.  I have both monitors hooked up to a switch, with one cable going to my personal desktop and the other going to my work laptop.  When I remove the switch from the equation and just run the cables straight from my video card to the displays, they both run at 3840x2160 @ 60Hz and look good.  Both switches are the same make and model, but maybe one of them isn't as good as the other somehow, or maybe one cable being DVI while the other is HDMI has something to do with it.  Is one cable type better than the other for these things?  I've never considered that until now, but maybe DVI is better because it's dedicated video and not also carrying sound?  I dunno.  The connections from my work laptop are both Display Port, but then they run into the switch, which then becomes HDMI.  When displaying my work laptop, the best the monitors can do at high resolution is 30Hz for both, but the video card is either integrated or nothing special, so I don't expect it to provide the performance my $600 GPU does.  Anyway, I think I need to play around more with different configurations to see what works best, or maybe see if I can find a higher grade switch.  

billsey

What make and model is the switch? They often have limits on some of the ports...

darrel

It's this one from Techole. https://smile.amazon.com/dp/B07XM5TBSF/ref=emc_b_5_i
It got lots of great reviews, so I went with it, and it actually works great.  I'm seeing in the description that while it does support 4K, it only does so at 30Hz, which now has me wondering why it even worked on one monitor.  They do offer another switch that has  an additional input port, and does 4K @ 60Hz, so I just ordered two of those, which will probably solve my problem.

billsey

Hmm, the blurb on Amazon says:

HIGH RESOLUTION: Support 3D, 1080P, 4K x 2K@30hz resolution

So I read that to say 4K is supported at 30Hz just as you found, it is odd that it works on one... Maybe they almost can handle it and you just got a golden build.