HDMI 2.0 cables

[V8covin]

I have 2 4k devices passing thru an amp to the tv.
I've just noticed there's no markings on the cables to say they are 2.0,in fact one has Sky branding on it and I haven't had Sky for some years.

If they're not 2.0 am I not actually getting a 4K picture or wouldn't I get a picture at all ?

[xeny]

Looking at https://www.tvcables.co.uk/hdmi-2.0-cables.html it may be a non issue. Similarly the sentence starting "Many HDMI cables" at https://en.wikipedia.org/wiki/HDMI#Cables

Can't the TV report what resolution it is displaying?

[V8covin]

Tv shows 2160p but that's because both devices are upscaling and set to that output