USB-C to DP 1.4 (Zephyrus G15)

I've got a G34WQC monitor (3440x1440 144hz) connected to my Zephyrus G15 2021.



I firstly bought this cable uni USB C to DisplayPort Cable 1.8m(4K@60Hz, 2K@165Hz) Thunderbolt 3/4 to Display Port Cable which shows in the description it's DP 1.2 and noticed a couple of times that it was running in Limited - YCbCr - 100hz. But a reboot it went back to Full - RGB - 144hz. This only happened a couple of times but it made me need to check it every so often, so I thought I had a bad cable and decided to get a certified 1.4 DP one.



So, I bought this one: USB C to DisplayPort Cable 8K@60Hz Maxonar 4K@60Hz/144Hz/120Hz 5K@60Hz 2K@240Hz Thunderbolt 3 to DisplayPort Cable HBR3 DP 1.4 Adapter

Upon connecting this one, I instantly get a removable device called Bilboard and it popup notification shows DP connection is limited. Does this mean faulty cable or is there something weird going on with the laptop itself? I found it weird as this cable is supposed to carry more "bandwidth" than the other one?



Anyone experienced similar? Or has any ideas?



I also have a second question. I'm running Windows 11, fresh install, everything's working correctly. But I noticed that when I have a full screen youtube video on the laptop screen (doesn't matter the quality) that on the main external one, scrolling, dragging windows, minimizing and maximizing become really jaggy and stuttery. If I stop playback it goes back to buttery smooth. Now, as I've said above, my external screen is 144hz, the internal is 165hz but I'd assume that a laptop this powerful (external plugged straight to 3080 through DP) would be able to handle this very easily. My £450 Honor Magicbook Pro (4600H CPU) handles this perfectly, though the internal display is 60hz, not sure if that's the problem here! Any ideas on this as well?



Many thanks!

 

Well, not directly related to DP I have played with the thought of using C power adapter power cables on a non-C recharging laptop. The cables vary greatly in what they do and what you get vs what they say you can do with them.

With that said here's what I suspect is going on. Cable 1 might be a bit defective if it's switching modes w/o reason. Cable 2 seems to me to have a chip inline that's causing the pop up to appear.

I don't personally do DP but, I'm familiar enough on how it should work if implemented. Looking at both cables they seem to have high reviews and number of reviews

When I'm looking for cables I tend to weed out the crap versions by going with the highest spec available for the cable.

C / 100W / 10gbps / etc. Now it would be 20gbps since that's the highest data rate outside of using TB @ 40gbps. For DP 8K seems to be the target for a more quality cable. Looking at the UK version of Amazon and searching for "usb-c dp cable 8k" comes up with a lot less results than the US side. To keep things local for shipping / VAT / import costs .

https://www.amazon.co.uk/Certified-Cable-Matters-Support-Charging-Black/dp/B08Q79BY1X
https://www.amazon.co.uk/Displaypor...t-Adapter-1-6FT-0-5M-without-PD/dp/B098SXVXWP

When in doubt pay up for startech as they're the benchmark typically for most tech after market items IMO. I've yet to run into one of their items that didn't work as needed.
https://www.amazon.co.uk/StarTech-com-DisplayPort-Cable-60Hz-Bidirectional/dp/B083YZWLWL