Question LG 43SQ700S 4K Resolution Capped at 30Hz Only for Windows PC via Thunderbolt/USB Typc-C Connection

[Routing1256]

Monitor

• LG 43" MyView Smart Monitor (43SQ700S) with USB Type-C and 4K UHD Display

Windows Device (4K 3840x2160 resolution capped at 30Hz)

• System Model: HP EliteBook 660 16 inch G11 Notebook PC
• System SKU: 9Y2V8AV (This is a model sold to SMBs in Japan, offered to me by the company I am working for)
• Processor: Intel(R) Core(TM) Ultra 7 165U 1.70 GHz
• Display Adapter: Intel(R) Graphics
• Display Output Ports: 2x Thunderbolt 4 40 Gbps ports, 1x HDMI 2.1 port
• OS: Windows 11 24H2 (26100.1)

Mac Device (4K resolution works fine at 60Hz)

• Model: MacBook Air (M2, 2022 · Z15T002LTJ/A · Mac14,2)
• Display Output Ports: 2x Thunderbolt 4 Ports
• OS: macOS 15.1.1 (24B91)

Cables I tried

• USB Type-C cable that comes with LG monitor. Specs unknown.
• Anker 515 USB-C to USB-C Cable (Thunderbolt 4 Compatible)
• Anker USB-C to USB-C Thunderbolt 4 100W Cable (2.3 ft)

Troubleshooting I tried

The 60Hz option is available while followed by a star. When selected the resolution will be set to FHD 1920x1080 @ 60Hz.



I contacted HP support, and they asked me to enable "High resolution mode when connected to a USB-C DP alt mode dock" in BIOS settings. I did so but the refresh rate is still capped to 30Hz.

HP support also told me to uninstall display adapter driver in Device Manager, and reinstall it by using the exe file downloadable from their support site. This also did not work.

I also tried to set color format to YCBCR_444 in Intel Graphics Command Center but nothing happened.



The issue above only exists when connecting the HP laptop to the monitor with a single USB Type-C/Thunderbolt cable. HDMI cable works fine for the HP laptop.

I just cannot figure out whether this is a limit of the monitor, the cables, or the Thunderbolt 4 ports on HP laptop.

 

[helpstar]

update BIOS
update display drivers
update chipset drivers

 

[Routing1256]

update BIOS
update display drivers
update chipset drivers

All done but nothing changed.

I started to think it is an HP-specific thing.

My own MacBook Air and a friend's Dell XPS can achieve 4K@60Hz via USB Type-C/Thunderbolt connection without any problem.

HP Japan called me today and told me they are not responsible for any peripheral issue. I told them it is a Thunderbolt 4 port and should clear its bandwidth standard. They seem to avoid this issue.

 

[helpstar]

are you sure it´s connected to the TB port and not USB-C 40Gbps port? use the port with the flash symbol

I think this laptop´s max. reolution output using TB is "only" 4k @30Hz. So this is the max refresh rate you will get out of this monitor with TB using 4k. @1080p you will get 60Hz

edit:
https://www.lap4worx.de/media/pdf/ee/84/0f/HP-EliteBook-665-G11-QuickSpecs.pdf
search for resolutions

are you using a docking station?

 

[Routing1256]

are you sure it´s connected to the TB port and not USB-C 40Gbps port? use the port with the flash symbol

I think this laptop´s max. reolution output using TB is "only" 4k @30Hz. So this is the max refresh rate you will get out of this monitor with TB using 4k. @1080p you will get 60Hz

edit:
https://www.lap4worx.de/media/pdf/ee/84/0f/HP-EliteBook-665-G11-QuickSpecs.pdf
search for resolutions

are you using a docking station?

Thank you again.

The PDF you are looking at is the AMD variation of the product.

This should be the Intel version.
https://www8.hp.com/h20195/v2/GetDocument.aspx?docname=c08950679

It sats "2 Thunderbolt™ 4 with USB Type-C® 40Gbps signaling rate (USB Power Delivery, DisplayPort™ 1.4)" and the there is a flash icon besides the port.

DisplayPort™ 1.4 is capable of outputting 4k@60Hz...

 

[helpstar]

https://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c08915794

did you try using the monitor while the display is off?

 

[Routing1256]

https://h20195.www2.hp.com/v2/GetDocument.aspx?docname=c08915794

did you try using the monitor while the display is off?

Yes. I'm using the laptop with lid closed (clamshell mode).

 

[Misgar]

I think this laptop´s max. reolution output using TB is "only" 4k @30Hz.

That ties up with my media system with a GTX 1650. The GPU is only capable of 30Hz, despite the fact my TV can run at 60Hz. For watching films I'm not bothered about the lower refesh rate.