HDMI Cable Question

[Buadhai]

This on a 2019 iMac on 13.2.1.

I have an ancient Samsung Syncmaster XL2370 1080p Monitor which I use as an external display for the iMac. Originally I used a UGreen USB-C/HDMI hub/adapter which has one 4K HDMI port and three USB-A ports connected to one of the Thunderbolt ports on the Mac. This worked just fine with any old generic HDMI cable.

Then I inherited a brand new OWC Thunderbolt hub (3 Thunderbolt ports). I connected that to the Mac and then connected the UGreen adapter to the OWC Hub. That caused the old Samsung display to be very unstable with lots of flickering. I tried every HDMI cable I could find in my keep-forever cable box and none worked.

So, I bought a new UGreen 8K HDMI cable, which now works fine.

Question is, why does the OWC hub create the need for a high quality cable when without the OWC hub any old HDMI cable works fine?

 

[satcomer]

Because you have to have HDMI high Speed HDNY to use with HDMI spec 2.0 to 2.1 for the newer 5-6K displays! Older cable don't have the bandwidth to do anything past 4K 30Hz!

 

[Fishrrman]

Satcomer, thanks for posting that.
But... could you clarify "HDMY"?
A search provides nothing (except "HDMI")...

 

[satcomer]

Satcomer, thanks for posting that.
But... could you clarify "HDMY"?
A search provides nothing (except "HDMI")...

The M was tying mistake sorry dude!

 

[Buadhai]

Because you have to have HDMI high Speed HDMY to use with HDMI spec 2.0 to 2.1 for the newer 5-6K displays! Older cable don't have the bandwidth to do anything past 4K 30Hz!

I understand that newer high resolution displays need newer HDMI cables. But I'm using an old 1080p monitor which works fine with older cables if I remove the OWC hub and just use the UGreen adapter.