How to spot fake cables?

Updated 4 days ago in Warranty questions
6 on 26-03-2021

Hi,

I purchased some Club3D cables from Amazon (Spain) and would like to know how to spot fake cables. I’ve had some (few) poor experiences with them in the past.

Furthermore, I would like to also benefit from having a warranty for the cables (is Amazon an authorized distributor?).

My main issue right now is issues with Level1Techs KVM + 3090 + an Odyssey G9 which isn’t liking DSC using 6+3 ft Club3D cables.

 

Bests,
T

 
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1 on 26-03-2021

HI TaiSHi,

Not sure what you mean. Which cables did you buy? Can you link the Amazon page? And what are the issues precisely?

 

on 02-04-2021

Hey Baak,

Just having some issues with DSC (I think). Here are the ones I purchased https://www.amazon.es/gp/product/B076D6GGG8/

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2 on 28-03-2021

DSC is not a function of the cable. It is compression done by the GPU. With compression, an error causes greater artifacts in the display. Without compression, an error is less noticeable.

Errors increase when you chain cables together, especially if they are passive (don’t contain a retimer or redriver or repeater to boost the signal for the next part of the transmission). I think the KVM is passive. I wonder what kind of switch it uses – or what components exist between the inputs and output of the KVM?

Is the 3090 transmitting HBR3+DSC or HBR2+DSC? I know that the Apple Pro Display XDR will use HBR2+DSC for 6K 60Hz 10bpc (1286 MHz). HBR2 is only 5.4 Gbps. HBR3 is 8.1 Gbps so it will have more errors. A G9 supporting 5120×1440 240Hz uses a pixel clock of 2018.5 MHz which can be done with HBR3 at 8bpc 4:2:0 or HBR3+DSC (at least 8bpc, not sure about 10bpc; 4:2:0 is a simple 2:1 compression method – DSC can do up to 3:1 and is smarter about what information it throws away).

Shorter cables may help. Maybe a DisplayPort 1.4 repeater will help. Maybe you can use an MST Hub as a repeater.

https://store.level1techs.com/products/14-display-port-kvm-dual-4ports
https://www.youtube.com/watch?v=wfJ1Hc96ZHo

on 02-04-2021

I’m not sure about what the 3090 is transmitting, how can I check?
I’m using 2x 3ft cables that’s as short as I could find

Also, that’s a lot of amazing info, appreciate it! I’m super noob on this and I’m trying to figure out where the issue is so I can address it

on 03-04-2021

I’m not sure if Nvidia exposes the info anywhere about when it’s using DSC. I don’t have an RTX card to test. Try the Advanced tab in GPU-Z?

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0 4 days ago

What is it not doing? You have not said what is not working. What results are you expecting from your setup what are you getting?

Pretty sure the botheneck is the KVM.

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