Did I buy a dodgy HDMI cable?

ne0 · 5 Aug 2022 at 19:14

Hi folks

I wanted to hook up my 4k hdr tv to my gpu via hdmi so I can play more chilled games on it.

I bought a 4 metre hdmi 2.0 4k 60hz cable from Amazon for about £8 and having some problems so wanted to check with more knowledegable peeps as to whether I bought a dodgy cable which is what I am suspecting!

Everything works fine until I send an HDR signal to the tv through the cable and then I get pixel artifacts...hard to explain but kind of empty pixels dotted all over the screen. Not only this but the tv will randomly flash its picture on and off.

Sending 4k, 60hz, 10bit WITHOUT switching on Windows HDR makes the white dots disappear but then the screen will randomly lose signal...only 8bit solves the problem.

Cheers

ne0 · 6 Aug 2022 at 10:59

Managed to sort it so leaving this to help anyone else in future.

Turns out the cable I bought going from PC to soundbar was fine - it was actually the cable I had going from soundbar to TV that wasn't up to the task - I guess Amazon basic cables are a little too 'basic' at times

Quartz · 6 Aug 2022 at 11:03

ne0 said:
I bought a 4 metre hdmi 2.0 4k 60hz cable from Amazon for about £8 and having some problems so wanted to check with more knowledegable peeps as to whether I bought a dodgy cable which is what I am suspecting!

I don't know about HDMI but with Displayport 1.4 anything over 3 metres was dodgy at 4k 60 Hz 8 bit on a copper cable. I went fibre.

MassiveJim · 6 Aug 2022 at 15:25

to get 4k 60 you need a "certified" HDMI cable, there is an official certification "body" and there are also lots of fakes around.

for a normal copper cable I believe the limit is 5m, and having recently bought one at that length it is a very thick cable.
to go over 5m you need an "active" cable and those are (relatively) expensive