2 x 4k 144hz Monitors from Laptop

[zedx19]

Struggling to figure out why this isn't working, when from the Googling I've done, suggests it should.

Dell XPS 9500, i7-10750H, 32gb ram, Intel UHD Graphics, Nvidia Geforce GTX 1650TI Graphics, this is connected to a Dell WD19TB dock and 180w power supply, all good so far. I did have 2 x 1080p 60hz Dell Monitors + the laptop screen on, worked fine for 2 years but I thought I'd upgrade to 27" 4k 144hz monitors. However when I've plugged these in, they are at the correct resolution of 2560 x 1440 but the refresh rate options are 59.95hz or 60hz only? The monitors are connected to the dock via Displayport cables, which came with the new monitors. The dock is connected to the laptop via the Thunderbolt port.

Google suggests the dock should be able to handle it, as should the laptop, any ideas why I can't get 144hz?

[Condi]

https://www.eaton.com/us/en-us/products/backup-pow...

This suggests DisplayPort cabling won't do 4k @ 144hz.

[.:ian:.]

144hz is pretty niche and doesn't show up as a recognised refresh rate very much.
The specs for both the dock and the igpu only mention 60hz which is clearly wrong.

4k resolution isn't 2560x1440? Are they 4k monitors?

Does it work with 1 external monitor and the internal display off?

[TheGroover]

See also here

[snuffy]

That resolution is 2K.

But to be fair, everyone where I work thinks that anything above HD is 4k.

[zedx19]

Thanks for the replies, my mistake, they are 2k monitors, the resolution in Display Settings matches the product, it's the refresh rate which doesn't.

I have tried 1 monitor on its own and 1 in DP with the other usb c to HDMI, still on 60hz is available.

I'm thinking to just leave it unless it's an easy fix, I do CAD work mostly, the extra screen space is a massive benefit, the resolution would have just been a nice bonus.

[paulrockliffe]

Skip the dock and go direct with a cable you know is high enough speed for 144hz.

[xeny]

paulrockliffe said:

Skip the dock and go direct with a cable you know is high enough speed for 144hz.

Still not enough - see https://ark.intel.com/content/www/us/en/ark/produc... the maximum supported refresh rate for the integrated graphics is 60Hz at 4K.

Annoyingly the discrete GPU doesn't support external displays at all. - https://www.dell.com/support/manuals/en-ca/xps-15-...

[mmm-five]

Unless you're gaming, why do you need 144Hz refresh rate?

The resolution & screen size are all that should matter for media/productivity work.

Does "max graphics of 4k @ 60Hz" also mean that the max refresh rate - no matter the monitor or resolution is 60Hz?

Dell said:

Intel UHD 630 Graphics supports up to the following resolutions and refresh rates:

• DP: 4096 x 2304 @60 Hz, 24 bpp
• DP: 4096 x 2304 @60 Hz
• USB type-C Alt mode: 4096 x 2304 @60 Hz
• VGA: 1920 x 1200 @60 Hz
• HDMI2.0: 4096 x 2160 @60 Hz

The 60Hz limit might be due to due to the iGPU in the 10th Gen CPUs only supporting DP1.2 (in most cases).

Edited by mmm-five on Thursday 28th March 14:27

[zedx19]

xeny said:

Still not enough - see https://ark.intel.com/content/www/us/en/ark/produc... the maximum supported refresh rate for the integrated graphics is 60Hz at 4K.

Annoyingly the discrete GPU doesn't support external displays at all. - https://www.dell.com/support/manuals/en-ca/xps-15-...

Thank you, case closed, I'll stick with the additional screen space at 60hz, going from 2 x 24" + laptop to 2 x 27" + laptop seems to have been a bigger jump than expected. I've started using Fancyzones to make full use of the screen space.

[xeny]

Actually not closed - I just read the OP more carefully rather than concentrating on the subject - you aren't describing 4K monitors from the resolution you give of 2560 x 1440. 4K is 3840 x 2160.

I'd agree it would be worth trying plugged directly into the laptop via USB-C to DP cables.

Looking at the Dock's data sheet https://www.delltechnologies.com/asset/en-us/produ... the max refresh rate supported at any resolution is 60Hz.