HDMI max length for Projector 1080p / 4K

pioneer2000

pioneer2000

pioneer2000

Soldato
Joined
20 Jun 2004
Posts
5,936
Location
Essex
Just setup my projector (Optoma HD25e) after a year in storage... though discovered that my previous HDMI lead isn't long enough for the new room (I think it's a 10m lead but need 15m or thereabouts).

Now i'm aware that HDMI isn't technically supposed to work over such long distances but the 10m one always worked fine at 1080p, so guessing 15m should be ok?

I wanted to future proof by getting a HDMI 2.0b / 4K compatible cable (now I realise a lot of it is snake oil but there are definitely some quality differences at these sort of distances, in the budget HDMI arena).

In doing some research it seems that HDMI 2.0 states a maximum of 3m for 4K HDR... so how on earth do people wire up 4K projectors with only 3m to play with?

I'm guessing there's no way to get a cable that would definitely work at 15m if I ever went 4K?
 
So essentially none of the cables I'll find on Amazon (at a reasonable price) will work at 18Gbps (4K HDR 60hz) and I might as well just buy any old one that will work at 1080p at 15m and forget about future proofing if I ever buy a 4K projector?
 
pioneer2000 said:
So essentially none of the cables I'll find on Amazon (at a reasonable price) will work at 18Gbps (4K HDR 60hz) and I might as well just buy any old one that will work at 1080p at 15m and forget about future proofing if I ever buy a 4K projector?
Click to expand...

It's going to take a while for manufacturing to catch up. If you have 2 plants in the world capable of making cables to the spec required to do UHD @ 60Hz for a 15m cable then of course the cost will be high. When it's 100 plants then the cost gets lower. That's what happened when HDMI was first introduced. It happened again in the change to 1080p; and again when they broke the 5m and 10m and 15m barriers. It'll happen again with UHD @ 15m, but will take a while due to demand and the fact that 18gbps over distance is right at the edge of the performance envelope.

The best you can do right now is plan to make it easier to change the cable once prices get to within your reach. You do that by putting the cable in in such a way that it's easy to pull a new cable through. That, or you bite the bullet now and spend the cash.
 
lucid said:
It's going to take a while for manufacturing to catch up. If you have 2 plants in the world capable of making cables to the spec required to do UHD @ 60Hz for a 15m cable then of course the cost will be high. When it's 100 plants then the cost gets lower. That's what happened when HDMI was first introduced. It happened again in the change to 1080p; and again when they broke the 5m and 10m and 15m barriers. It'll happen again with UHD @ 15m, but will take a while due to demand and the fact that 18gbps over distance is right at the edge of the performance envelope.
Click to expand...
They catch up just as the new HDMI 2.1 with 48Gbps bandwidth comes out....:D
 
Amazon have a 15m cable that uses Redmere that they rate for 18Gbps. Does your projector or AVR have HDMI cable testing facilities or do you have a way of testing them? If so, you may as well buy it and test it, if it doesn'tdo 18Gbps, send it back.
 
Last edited:
jpaul said:
interesting so the spectra7 active 50ft cables are £40 + customs
https://www.amazon.co.uk/Monoprice-114471-Active-Speed-18Gbps/dp/B019FN6II0
would want a good warranty though
Click to expand...
So going by the reviews that 50ft HDMI cable does not work...

Verified Purchase
Not as advertised. Will not pas 4K 60P HDR HDCP 2.2. Tested by connecting Roku Ultra direct to 4K DLP projector. I could use a 6' Premium Certified cable and it does get 4K 60P HDR with HDCP 2.2, but every time I switched to the HOSS cable it would fail HDCP 2.2. I switched multiple times. Today is one month and Amazon no longer allows the option to return, so looks like i am stuck with this piece of junk, so warning others, not to buy.
Click to expand...
Verified Purchase
This did not work at a 50' run as advertised. This is the same as the Luxe and Dynamic View series, with the only difference being the thickness of sheathing being significantly greater here. The chip simply does not work as advertised at the 50' length
Click to expand...
Verified Purchase
My TV only supports HDR at 30hz which does work, I can say that RGB full dynamic range does not work from a computer though, it worked temporarily until I turned the tv off and on then no signal, works flawlessly at 4k 60hz YUV 4:4:4 though.
Click to expand...
 
This has been the problem since HDMI started. Very few companies really understand the technicalities of what they're having made and then marketing. Many simply rely on the manufacturing plant operating companies to say what standard the cable conforms to; but they don't check that the certification is (a) genuine or (b) applicable to each specific length, or (c), that the cable spec hasn't been altered since testing.
 
Does anyone know if Redmere limits the bandwidth that the cable can transmit? i.e. If the Amazonbasics cables are only the 10Gbps version of Redmere, does this mean that's all it can transmit, or could it still work at 18Gbps despite the limitations of the chipset?
 
My understanding of Remere has always been that its about being able to use much thinner cable rather than trying to extend length or run at higher resolutions.
 
To be fair how often are you going to be feeding 4k60 HDR 4:4:4? Pretty much never, maybe try and future proof the cable run at least with some plumbers tape or something but for now I assume 24hz is all you need which I bet a lot of cheaper cables will manage. 4k60 HDR from consoles is 4:2:0 anyway (afaik?).
 
pioneer2000 said:
Does anyone know if Redmere limits the bandwidth that the cable can transmit? i.e. If the Amazonbasics cables are only the 10Gbps version of Redmere, does this mean that's all it can transmit, or could it still work at 18Gbps despite the limitations of the chipset?
Click to expand...
indeed seems the chipset itself can cause problems - from earlier avfoum thread some people needed to insert power supplies, and also got better results with a passive cable.

this comment was fascinating
Just to put into context, the HT8181 was originally supposed to launch at Q1 2015, but HDMI spec changes and finicky consumer hardware kept pushing the date back. HDCP and HDMI 2.0 are so sensitive that noise was introduced into the signal because a perfect signal would trigger content protections.
Click to expand...

I cannot see anyone who chained two of their cables ... surely a repeater (in the middle) strategy is more viable ?


.... samsung have fibre optic - no ? from box to the tv ... can't they commercialize that ? would go for miles ... (no drm i imagine)
 
Chris1712 said:
To be fair how often are you going to be feeding 4k60 HDR 4:4:4? Pretty much never, maybe try and future proof the cable run at least with some plumbers tape or something but for now I assume 24hz is all you need which I bet a lot of cheaper cables will manage. 4k60 HDR from consoles is 4:2:0 anyway (afaik?).
Click to expand...

Sure, likely 4K 60hz from my X1X is the max id put through it... what bandwidth does that equate to then? Has to be more than the 10Gbps that any standard hdmi cable can do over 15m?

I’ve got a RedMere cable coming (was too late to cancel it) so can test tonight. If I connect my X1X direct to my LG B7, the 4K test screen in the dashboard should indicate if it’s all working, shouldn’t it? (I’m thinking 4K, HDR and all the jazz that it lists ticks by in that menu)?
 
You must log in or register to reply here.
Back
Top Bottom