Why is HDMI 2.0 cable required?

QuestionsCategory: AVWhy is HDMI 2.0 cable required?
El Hefe asked 9 months ago

Currently, I connect a Samsung UBD K8500 4K player via a Denon X6200W AVR to a Samsung UHD TV on its HDCP 2.2 port. I use my existing HDMI 1.4 cables in the whole picture chain for this set up.
The data from Denon AVR shows that input from Samsung player and output to TV are both at 3840 x 2160. Also the same on the TV is showing 3840 x 2160 input from the Denon AVR.
While online articles say that a HDMI 2.0 cable is required to get the full 4K potential, what is the technical explanation of the need to use a HDMI 2.0 cable?
 
Thanks.

6 Answers
lam seng fatt answered 9 months ago

El Hefe had to ask a question that was difficult to answer. I passed the question to a few dealers in Malaysia and Kenny Lim of Audio Perfectionist said he would forward the question to Kordz cables, which makes high-end cables including HDMI cables.
James Chen of Kordz replied and his answer is in the next post.

El Hefe replied 9 months ago

What to do…. still learning? Hehehhe.

james chen answered 9 months ago

There is no such thing as an hdmi 2.0 cable.

HDMI website will also say this.
http://Www.hdmi.org
Actually there is also no such thing as an hdmi 1.4 cable.
You only need a high speed hdmi cable to get current generation 4k.
I hope this helps.
All the best,
James

El Hefe replied 9 months ago

Thanks James,

Now it gets confusing. There are a lot of references to HDMI 2.0 and 1.4 even on the hdmi.org page. I might use the wrong terms i.e. cable instead of specification.

If I were to reiterate the question…. since a 1.4 (or existing hdmi cable) is already projecting the required 4K resolution (and not getting into the 4K Half discussion)…. what will the hdmi 2.0 do more than existing hdmi cable?

From your comment, it looks like…. we do not need a new HDMI cable for 4K. Correct?

http://www.trustedreviews.com/opinions/hdmi-2-0-vs-1-4

http://www.hdmi.org/manufacturer/hdmi_1_4/index.aspx

http://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0_faq.aspx#118

http://www.cablestogo.com/tech/hdmi-2

lam seng fatt answered 9 months ago

This is what I found in the hdmi.org website:
 
Choose the Right HDMI Cable for the Job
Selecting the right HDMI cable depends on the level of video resolution and features you intend to support, and whether or not you want Ethernet connectivity. Genuine HDMI cables are clearly labeled to make this process easy:



Built for most home applications, the Standard HDMI Cable can reliably transmit 1080i or 720p video.



Standard HDMI Cable performance, plus a dedicated Ethernet channel for Internet connection sharing and device networking.



Designed to support video resolutions of 1080p and beyond, including advanced display technologies like 3D and 4K.



High Speed HDMI cable performance, plus a dedicated Ethernet channel.

Premium High Speed HDMI Cable and Premium High Speed HDMI Cable with Ethernet are designed for ultra-reliable performance for 4K and advanced features such as higher frame rates, HDR, expanded color spaces including BT.2020 colorimetry, 4:4:4 chroma sampling, and are identified with the Premium Certified Cable Label
 
 
 
 
 

Dick Tan answered 9 months ago

According to the standards recommended by the HDMI Consortium that presides over HDMI standardisation, HDMI cables that are to be used in a full 4K (UHD) system should comply with its HDMI 2.0 rating .  So, if you are working to build-up a 4K system, the prudent thing to do  would be to acquire HDMI cable with the 2.0 rating.
Why HDMI 2.0 ?  Well, once again, according to the HDMI specs laid down, a HDMI  2.0 cable will have a high enough transmission speed of at least 18 Gbps required to pass through  high resolution; high density signals.
Official HDMI specs for HDMI 1.4 cable transmission speed at full rate is up to only 13.5 Gbps.
In a worst scenario situation  where the HDMI cable is not up to speed no picture, will be transmitted or the picture due to a slower speed will be distorted or discoloured.
While UHD Bluray is primarily about increased resolution (four times that of conventional Bluray) it is also about increased colour bandwidth,  wider colour gamut and High Dynamic Range picture.  And while your system as you described may show a passing of 4K signals along your equipment chain there is no guarantee that it will pass along the rest of the visual benefits mentioned.
Lastly while there exist HDMI specification standards it is now clear, at least to me, that  whatever icons are printed on the cable is not really an accurate indicator of what the particular cable can or can not do. 
There are many cables out there, even if they are just printed with a HDMI 1.4. or even lower spec is actually capable of transmission speed in excess of 18 Gbps.  That will explain why you are able to get a UHD Bluray signal.  A further clue Iies in the components you are using…. all of them from the player to receiver to display are, at least as the published specs go,  fully 4K compatible. 
I have a system with specifications similar to yours and I use a long 10-metre HDMI 1.3 rated cable to connect via a Pioneer SC-LX88 receiver to my JVC projector which is of native 1080p resolution but scaled to 3840 x 2160 UHD specs.
You know what?  I get a beautiful, bright, highly detailed picture on my 110″ 2.35.1 screen!
In a nutshell,  and I am by no means advocating you buy cheap generic cables, the HDMI connector /cable format while having been with us for a long time now is still very much an unchartered minefield when it  comes to the full understanding of its specifications. 
As James Chen of Kordz says… there’s no such thing as a HDMI 1.4 or 2.0 cables.  If that’s the case why do some manufacturers make the claim?  Marketing expediency?
Perhaps it is more expedient to consider this….  get your HDMI cables from a trusted dealer.  If he values your business he will accommodate your trying out the cables to ensure they work.  Not very scientific perhaps but at least you know that is the safest and sure way to ensure you do not end up with an unnecessary hefty bill.

ST replied 9 months ago

Generally, you don’t!

Your HDMI 1.4 can transmit up to 10.2Gbps which is good enough for your 4K material up to UHD @ 30Hz which requires a total bandwidth of 8.91Gbps. Check your source to be sure not to exceed UHD@30Hz and keep your cable short.

El Hefe replied 9 months ago

Thanks Dick,

This is what I am trying to get to. To clear up the understanding of minimum requirement for setting up a 4K system. Yes, I agree that purchasing a well built cable has its own merit. But I am still baffled on whether we need to change our existing HDMI cables to the 2.0 specs.

El Hefe answered 8 months ago

I think I can summarize it as HDMI 2.0a is only required for HDR. …. For 4K standard without HDR, existing 1.4 cable is sufficient.

STC answered 8 months ago

According the standards, HDR only demand about 20 percent increase in the bit rate.  As I mentioned earlier above,  4K at 30 frames plus HDR may just be within 1.4 cables limits.  What is the highest frame rate you have watched so far?

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