Mac mini USB-C to Displayport non-smooth scrolling with Magic Mouse, but USB-C to USB-C is buttery smooth

[SSD-GUY]

Hi all

Bit of a weird query

I've got a Mac Mini connected to my LG 27UD88 display. When I connect it via a USB-C to Display Port cable, the scrolling is not very smooth with the Magic Mouse. That being said, if I use my Belkin USB-C to USB-C cable plugged into the monitor, the scrolling is buttery smooth.

Is this a limitation with Displayport? If not, can someone recommend a better USB-C to Displayport cable?

Thanks

 

[joevt]

Do both connection types give the same refresh rate?

USB-C to DisplayPort an USB-C to USB-C should have the same performance. USB-C has separate lines for DisplayPort and USB.

In fact, I would expect the USB-C to USB-C connection to have issues if it is also used as USB upstream connection and the USB ports of the display are operating as USB 3.0. In that case, I would expect the display to be limited to 30Hz since two of the four USB-C lines would be used for the USB 3.x data. If the display supports DSC (Display Stream Compression) then two lines of DisplayPort is sufficient for 4K. But DSC is a feature of DisplayPort 1.4. The specs say the display supports DisplayPort 1.2. Maybe they mean it supports DisplayPort 1.4 at HBR2 link rate.

I would connect the display to an Intel Mac and use AllRez to get info about the display and display modes.

 

[Fishrrman]

"That being said, if I use my Belkin USB-C to USB-C cable plugged into the monitor, the scrolling is buttery smooth."

Fishrrman's "#2 Rule of Macs":
Use what works for you.
Don't use what doesn't work.

 

[pshufd]

Are there limitations on the DisplayPort cable? If so, just buy a cable that's rated for the resolution and frequency that you want. I have had good luck with Cable Matters cables.