Dave Upton

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When I received my new LG OLED 48CX from Value Electronics, I was excited to start gaming at 4K and 120Hz with full 4:2:2 or better chroma, but found myself in a bit of a quandary. I had a lengthy (11 ft) run to my PC,and my existing HDMI cable could not handle the goal of pushing 4K 120Hz @4:2:2 chroma content despite my best efforts, as this exceeds the bandwidth an 18Gbps HDMI cable can handle. A brief bit of research found Monoprice and their SlimRun optical HDMI cable series.
If you haven’t been paying close attention, you may not have noticed that HDMI cables have come a long way in the past couple of years. New HDMI 2.1 compatible cables that support 48Gbps bandwidth are now hitting the market, with a myriad of affordable (but not necessarily reliable) cables available at Amazon and other online marketplaces.
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Edwin-S

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How do these work? As far as I know, HDMI connectors on AV receivers and TVs are not optical connections.
 

DaveF

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How do these work? As far as I know, HDMI connectors on AV receivers and TVs are not optical connections.
There's a small electro-optic (EO) device that converts the electrical digital signal to optical digital signal at the input side. That propagates by fiber. At the output side is another EO device to do the opto-electronic version back.

(to my surprise, I can't easily find a "how's it work" website 'splainer on this. so you'll have to take my word for it. :) )
 

Edwin-S

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There's a small electro-optic (EO) device that converts the electrical digital signal to optical digital signal at the input side. That propagates by fiber. At the output side is another EO device to do the opto-electronic version back.
Thanks for the reply. Another question. I bought some new cables for the LG 77 OLED set I'm putting in. The set is capable of up to 120Hz refresh rates. The panel is 10 Bit so the fastest data transfer is a maximum of 40 GB/s according to their spec. The cables I bought are rated up to 18 GB/s. Cables tend to have a lot of snake oil attached to them, so I'm trying to decide if the ones I bought would support higher throughput, since they say the cables support up to 16 bit deep colour. 12 bits is like 48 GB/s, so I'm trying to figure out how a cable can be rated for 16 bit colour while saying it is an 18 GB/s throughput. These things cost a bit, so I want to make sure that they will be able to handle above 18 GB/s if the need arises, otherwise I want to return them which kind of screws me up for hanging the set since I would have to order up to 8K capable cables, since none of the stores locally have anything in the length I need.

Are these monoprice optical HDMI cables made in lengths of between 10 and 16 feet? The ones I found on Amazon.ca all seem to be longer than 25 feet, which is overkill for my installation.
 

Edwin-S

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...which is why these cables start at $200.
The cables I bought were C$150 per cable. The set I bought has cost as much as a good used car so I guess putting out dollars for the cables is small change now, just so long as they do the job. Unless, you can recommend reliable 48GB/s copper cables since the longest distance I'm going to is ~16 feet.
 

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These optical cables are AFAIK meant for long runs, 30’+ where regular cables have problems with signal loss and degradation. If you have a short run, there are plenty of conventional, electrical cables that are much cheaper.
 

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Dave, the simple answer is that 18 Gbps will cover all 4K including any HDR, and 48Gbps covers all currently proposed 8K. So the question is, what’s the chance of going 8K in the foreseeable future?

The middle of last year I just went ahead and replaced every hdmi cable in the house with the middle cables you linked. One cable is 15’ and I opted for an active cable, just to be safe.
 
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Edwin-S

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I'm mostly looking at the 48 GB/s cables because the 18 GB/s cables are certified for 4K/60 4:4:4, while the 48 GB/s cables allow 4K/120, which is the native capability of LG's 2020 OLEDs. The set will be used for gaming as much as for watching TV and films.
 
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Dave Upton

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Dave, the simple answer is that 18 Gbps will cover all 4K including any HDR, and 48Gbps covers all currently proposed 8K. So the question is, what’s the chance of going 8K in the foreseeable future?

The middle of last year I just went ahead and replaced every hdmi cable in the house with the middle cables you linked. One cable is 15’ and I opted for an active cable, just to be safe.
This is mostly true for HT use where frame rates are at or below 60 Hz, but isn't true for PC or gaming console use. As you go to greater chroma and refresh rates, you'll easily surpass 18Gbps which is why the HDMI 2.1 specification was ratified. The below table shows that even in a home theater as you go beyond 4:2:2 chroma you need >18Gbps.

Now, at 4K, 120Hz 4:2:2 you will need 32Gbps, at 4:4:4 you'd need the full 48.

1604333870943.png


The reason I consider these cables worth it is more due to reliability - the handshake is instantaneous, and once you start pushing the envelope past 20Gbps a lot of these copper cables start to have issues. I prefer to buy a cable that will work flawlessly for the next 5 years and call it good.
 

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JohnRice

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Good info @Dave Upton . I don't dig into gaming or that other esoteric stuff, but I need to clarify when I talk about cables. For standard home theater, you're talking maximum 4K 30Hz, and 18 Gbps is suitable, even up to 4:4:4 12 bit. Isn't HDR used for movies all 10 bit?

When I replaced all my cables a couple years ago preparing for a 4K upgrade, I didn't see any 48 Gbps cables. All my cable except one are 6' or less, so the cost is rather minimal. Since I already did it and don't see 8K soon, if ever, in my future, I guess I'm safe.
 

Edwin-S

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This is mostly true for HT use where frame rates are at or below 60 Hz, but isn't true for PC or gaming console use. As you go to greater chroma and refresh rates, you'll easily surpass 18Gbps which is why the HDMI 2.1 specification was ratified. The below table shows that even in a home theater as you go beyond 4:2:2 chroma you need >18Gbps.

Now, at 4K, 120Hz 4:2:2 you will need 32Gbps, at 4:4:4 you'd need the full 48.

View attachment 81335

The reason I consider these cables worth it is more due to reliability - the handshake is instantaneous, and once you start pushing the envelope past 20Gbps a lot of these copper cables start to have issues. I prefer to buy a cable that will work flawlessly for the next 5 years and call it good.
So are there any available in the 10 to 16 foot length? The information that 4K, 120Hz, 4:4:4 requires the full 48 GB/s is a bit annoying as these LG 2020 sets have a max input uptake of 40 GB/s due to using a 10 Bit panel. That means the max would be 4K, 120Hz, 4:2:2. More planned obsolescence as I suspect 12 bit panels will be the next "innovation".

Guess the limits on the LG 77 GX will have to do. The bloody thing cost an arm and a leg. I'm done with buying TV sets for the foreseeable future. This one will have to fail before I replace it, so if that happens I hope it will be within the five year extended warranty period. :)
 

Dave Upton

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So are there any available in the 10 to 16 foot length? The information that 4K, 120Hz, 4:4:4 requires the full 48 GB/s is a bit annoying as these LG 2020 sets have a max input uptake of 40 GB/s due to using a 10 Bit panel. That means the max would be 4K, 120Hz, 4:2:2. More planned obsolescence as I suspect 12 bit panels will be the next "innovation".

Guess the limits on the LG 77 GX will have to do. The bloody thing cost an arm and a leg. I'm done with buying TV sets for the foreseeable future. This one will have to fail before I replace it, so if that happens I hope it will be within the five year extended warranty period. :)
There are. The ones I am reviewing right now from RUIPRO are here: https://amzn.to/3jRRXT1

Monoprice has their version also: https://amzn.to/35WpBlA
 

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But for my theater I’m probably going with an ethernet extender. I currently have Cat5 run in wall with an HD capable ethernet extender. Not sure it does 4K. I think it’s easiest to buy a new extender than to attempt to get an HDMI cable through the run.

4K HDBT Extender Kit HDR 18GBPS HDMI Over Single CAT5e CAT6 CAT7 2.0B 4K @ 60hz UltraHD YUV 4:4:4 Uncompressed 230FT 70M Transmitter Receiver IR RS232 HDCP2.2 CONTROL4 Savant Home Automation 4K2K
by No Hassle Audio Video
Amazon product
J-Tech Digital HDBaseT [email protected] HDMI Extender [email protected] 4:4:4, HDMI 2.0 Over Single Cable CAT5e/6A up to 230ft (1080P) 131ft(4K) Supports HDMI 2.0 18Gbps, HDR, HDCP 2.2, RS232, Bi-Directional IR
by J-Tech Digital, Inc
Amazon product
 

Dave Upton

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I'm a big fan of HDBaseT - but be warned it is not nearly as reliable as you might think. I personally had issues with all the HDBaseT devices I tried.
 
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Edwin-S

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When do you think you will have your review on the RUIPRO cables up? Those are a bit cheaper than the monoprice cables. Still would be expensive since it looks like I would have to order them from Amazon in the States rather than the Canadian site.
 

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