Intel HD Graphics 530 Driver Problem Dual Monitor Maximum Resolution

[stylianosc]

Hello,

I have a laptop with an intel 530 as well as an nvidia 1060 GPU. I have connected 2 monitors on the intel integrated GPU through a USB-C dock and I got them to work, however, the resolution on the second monitor is limited to 1920x1080, even though its maximum resolution is 2560x1440. I have dual-boot and on the Ubuntu OS the resolutions work as expected to their maximum, but on the windows 11 OS, this problem is still there.

On the intel GPU settings app I can see the resolution listed for the monitor, but when I go to system settings, it's not available.

Due to this occurring on windows but not on ubuntu I am confident it's a software/driver issue and not hardware, so I would like to ask if there is a way to fix this. 

I read about the CustomModeApp.exe app, but I can't find it. I have tried CRU too without much success.

[n_scott_pearson]

We need a lot more information to even speculate on what the issue is.

What is the connection (resolution and frequency) that each of the two monitors is (separately) achieving on Linux?

In that timeframe, the DisplayPort 'tunnel' within Thunderbolt or USB-C (with DisplayPort Alt Mode) ports is diminished - literally halved - if support for USB is also active. For example, if you connect a monitor directly to the USB-C port, it will be able to achieve the full 4K@60Hz that is possible with a DisplayPort 1.2 channel, but when USB is also active - which is the case with a connected dock - this same monitor will only be able to achieve 4K@30Hz. In terms of data rate (throughput), an isolated monitor can use up to 17.28Gb/s while that same monitor can only use 8.64Gb/s if USB is also active.

So, all that said, let's look at possibilities. Wikipedia (here) provides information on data rates that are possible for various resolutions and refresh rates. Understanding our limitation (i.e. 8.64Gb/s), we can look at possibilities.

• Two 1080p monitors can be supported at 60Hz.
• Two 1440p monitors can be supported at 30Hz.
• Two 1440p monitors cannot be supported at 60Hz.
• If one 1440p monitor is blindly supported at 60Hz, there is only enough bandwidth left to support the second 1440p monitor at only 1080p resolutions.

If compression - DSC 4.2.0, for example - is enabled, I could see two 1440p monitors being supported at 60Hz (presuming no data loss in the dock and monitor cabling). The question is whether the first monitor is actually being connected using DSC.

A DXDIAG report would be helpful here.

...S