HDMI cable length

[talino]

Hi all,

I'm outputting 1080p video from my (aging) 2007 MacBook, which works pretty well except for some very detailed scenes. I'm using a mini-DVI to female HDMI converter, plus an HDMI cable. However, this last item is too short for me and I'm looking into buying a new one, around 7 or 10 meters. I don't know HDMI technology very well, and I'm surprised at the *huge* variety in prices (70 to 300 euros for a 10m cable). I was wondering if it was worth investing so much money in a cable — with no other cables running alongside it, and so without interference, is there a point in getting a cable almost as expensive as a BluRay player?

Thanks.

 

[deppest]

While I cannot give you a definite answer I can provide some info about my setup which includes a 10m HDMI between a WDTV Live and a HD cable TV receiver one one end (outputting at 720P, 1080p) and a HD projector on the other. I paid quite a lot for the cable at that time (a few 100s Euro from what I remember) and have never had any problems. It even works fine with a HDMI switch box which adds another meter between switch box and HDMI devices. Whether the same would have been true for a cheaper connection I don't know.

 

[Hellhammer]

http://www.monoprice.com/products/p...=10240&cs_id=1024005&p_id=3963&seq=1&format=2

30 feet (~9m) - 20$

I have 5m cable which I bought for 6€

 

[DragonJade]

I was wondering if it was worth investing so much money in a cable — with no other cables running alongside it, and so without interference, is there a point in getting a cable almost as expensive as a BluRay player?

Thanks.

These links may be of interest. They helped me decide to buy a cheap cable for my needs.

http://gizmodo.com/gadgets/field-notes/the-truth-about-monster-cable-266616.php

http://gizmodo.com/268788/the-truth-about-monster-cable-part-1-verdict-cheap-cables-keep-upusually

http://gizmodo.com/282725/the-truth-about-monster-cable-+-grand-finale-part-iii

 

[Cheffy Dave]

http://www.monoprice.com/products/p...=10240&cs_id=1024005&p_id=3963&seq=1&format=2

30 feet (~9m) - 20$

I have 5m cable which I bought for 6€

I am with you HH, Never had a problem with anything from Monoprice😎

 

[Fuchal]

In everyday use, expensive cables are the same as cheap ones.

 

[talino]

@DragonJade: Thanks a whole lot for the links which were a very interesting read indeed. I'll certainly try getting a cheap 30-feet cable first, like they suggest.

@Fuchal: I know that for "everyday use" cheap cables can handle the load, since my 6 feet entry-priced cable has been doing fine. I was specifically wondering about how they behave on longer distances (I'm a musician and the difference between balanced and unbalanced audio when using long cables is quite important).

The Gizmodo articles made me wonder about something else : they say that "real world" (i.e. as opposed to "future world") bandwidth requirements for 8-bit 1080p is around 1.6 Gbps. I am playing 1080p video from my NAS which is connected via a Gigabit switch, with no glitches (the ones I do have are caused by my MacBook's old CPU and crappy video chip). How is this possible, then? Is it because I'm playing it on a 24Hz projector (not likely, but it doesn't hurt to ask)?

Thanks again.

 

[Hellhammer]

Current high-quality 1080p Blu-Rays have bitrate of ~50Mb/s (1 hour film = ~22.5GB). You wouldn't be able to fit more than 4 minutes of video with 1.6Gb/s bitrate in a 50GB Blu-Ray. If I did my maths correctly, a 2-hour film with 1.6Gb/s bitrate would need 1440GB i.e. 1.44TB. Maybe some day 😉

 

[talino]

So when Gizmodo mentions 1.6Gbs, what are they talking about? Theoretical maximum bandwidth for HDMI?

In Part 1, they say:

The newest spec, 1.3a means just over 10Gbps of bandwidth. Standard 480p requires less than 1Gbps, the current 8-bit 1080p requires 4.46 Gbps.

In Part 2:

To simulate high-def video, it sends signal down one of three paths within an HDMI cable, so its signal at any given time is ONE-THIRD the bandwidth of that video format. The list of bandwidth tests we ran is as follows:

REAL WORLD
• 720p 8-bit 60Hz = 742 Mbps (x3)
• 1080p 8-bit 60Hz = 1.65 Gbps (x3)

Which comes down roughly to the same figure (1.65 x 3 ~= 4.46). This is much, much higher than the figure you're quoting (50 Mbps). What are they referring to?