MacBooks, monitors and DisplayPort: a primer

Wed, 10/15/2008 - 4:05am — Jonny Evans

Apple yesterday introduced a 24-inch LED Cinema Display and a range of MacBooks equipped with a Mini DisplayPort, and the company indicated this was a first step in transitioning all its products to DisplayPort. So what is it?

DisplayPort isn't an Apple technology - it's an emerging I/O standard that's designed for video - effectively in the running against HDMI.

DisplayPort was originally developed for computers in order to replace those horrid VGA connectors. It was introduced by the Video Electronics Standards Association in 2006.

We've been doing a little reading about it, and came across this excellent article on Electronics Design Strategy News we'd like to tell you about.

Unlike HDMI, DisplayPort is royalty-free. It's also open, which is probably why Apple like it. HDMI demands manufacturers pay a $5,000-$10,000 annual fee for use of it and a 4 cent per device royalty, despite this you'll see HDMI in consoles, TVs, DVD players, even the Apple TV.

DisplayPort offers a few advantages though: for example, while HDMI sends each colour over a separate data channel, with another channel for the TMDS clock and two more for device management and control; DisplayPort combines all the a/v and control information into packets, just like a data network. If you like, HDMI is based on old RGB type thinking, while DisplayPort is more like the internet - and therefore more potentially extensible.

Apple has chosen to deploy what it calls Mini DisplayPort, as noted by Electronics Design Strategy News: "DisplayPort enables thinner, smaller-form-factor monitors because the signal can go directly from the PC to the glass in the monitor in direct-drive, end-to-end configurations that replace LVDS with DisplayPort. In addition, the LVDS auxiliary channel is one-way, whereas DisplayPort’s bidirectional channel provides the ability to perform additional functions, such as notebook-backlight control."

So, in other words, the reason the new Macs don't have HDMI is because it is expensive to deploy and just isn't as flexible in its deployment as Apple required. DisplayPort is also easier than HDMI to integrate and implement in silicon.

Doug Bartow, strategic-marketing manager for the advanced-TV segment at Analog Devices, who participated in DisplayPort standards development said: "In our view, there are no consumer features in DisplayPort that distinguish it over HDMI,” he says. “As an engineer, I think that DisplayPort is a well-constructed display standard, and, if it were available three to four years ago, we’d all be using it. But HDMI is already here, and it will provide significant headwinds for market penetration of DisplayPort.”

Critics are already muttering disappointment that Apple didn't include an HDMI port on the new Macs, but perhaps it's fair to say they haven't yet familiarized themselves with DisplayPort, which is expected to appear as a port (as HDMI does) by 2010.

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Comments

Sounds good. If they release

Wed, 10/15/2008 - 5:28am — TTTimo (not verified)

Sounds good. If they release adapters so that older Macs can work with DisplayPort that will be even better, unless they are completely incompatible of each other.

I just think Apple is being

Wed, 10/15/2008 - 5:29am — Az (not verified)

I just think Apple is being cheap. Or they want to mess things up by going against the crowd. Sure DisplayPort is a little better, but it doesn't have the wide acceptance HDMI does.

Next thing we know Macs will be the only laptops to feature mini Ethernet.

Converter cables galore.

Flame me.

Sorry... had to closet the

Wed, 10/15/2008 - 6:11am — 9to5Mac Noob (not verified)

Sorry... had to closet the ol' flame thrower because of rising fuel costs.

hdmi

Wed, 10/15/2008 - 5:33am — Techslacker (not verified)

I believe Jobs stated that hdmi cannot push the data needed for Apple's 30" display. Considering this and Apple's target markets it makes sense to go with the DisplayPort technology.

Jobs is wrong. Hdmi can push

Wed, 10/15/2008 - 8:48am — toke (not verified)

Jobs is wrong.
Hdmi can push 10.2Gbps & 2560x1600 with single link.http://en.wikipedia.org/wiki/Hdmi

Oppenhiemer's product transition

Wed, 10/15/2008 - 5:35am — 9to5Mac Noob (not verified)

DisplayPort appears to be the mysterious "product transition" Oppenhiemer mentioned awhile back, because transitioning all products over to this new tech would surely affect margins.

i did about a half hour of

Wed, 10/15/2008 - 6:01am — 9to5Mac Noob (not verified)

i did about a half hour of searching yesterday...but i can't seem to find a male mini-DVI to female mini Display Port adapter. do such things exist? i'd really like to use this with my older macbook.

Please understand that Apple

Wed, 10/15/2008 - 6:19am — 9to5Mac Noob (not verified)

Please understand that Apple does not use DisplayPort - they use their own standard, this new mini-DisplayPort which was developed from the original DisplayPort. Apple now controls what you can do with this port. Apple provides the converters to old DVI.

Apple does NOT provide a mini-DisplayPort to DisplayPort converter, or mini-DisplayPort to HDMI converter. Hence, you cannot connect the new notebooks to devices which accepts standard DisplayPort or HDMI connectors.

Just another way Apple locks you in their world.

quote: "Critics are already

Wed, 10/15/2008 - 6:38am — Luis Alejandro Masanti (not verified)

quote:
"Critics are already muttering disappointment that Apple didn't include an HDMI port on the new Macs, but perhaps it's fair to say they haven't yet familiarized themselves with DisplayPort, which is expected to appear as a port (as HDMI does) by 2010."

As far as I can remember, USB was a "non to popular" device interface until Apple did their iMacs diskless and USB capable.

We can just specualate a little on the future of HDMI, but...

quote: "DisplayPort appears

Wed, 10/15/2008 - 6:45am — Luis Alejandro Masanti (not verified)

quote:
"DisplayPort appears to be the mysterious "product transition" Oppenhiemer mentioned awhile back, because transitioning all products over to this new tech would surely affect margins."

I think that "developing a full new manufacturer technology" for laptops is more related to "higher costs/lower revenues" in product transition.
But you have also the NVIDIA [laptops' chips] change and the new trackpads.

I do not mean DisplayPort is not important, but from a monetary point of view, it is "cheaper" (in the silicon and in the licencing).

"is because" is incorrect

Wed, 10/15/2008 - 7:09am — grammar police (not verified)

"is because" is incorrect grammar.

iMac/MacBook dock

Wed, 10/15/2008 - 7:15am — 9to5Mac Noob (not verified)

Seems no comments that this patent idea has been crossed off the list

http://9to5mac.com/imac-macbook-dock

I'm betting there'll be different, new Cinema Displays for desktops coming out soon. Including the 42", LED AppleTV!

Let the speculating begin!

Two notes: -Although I

Wed, 10/15/2008 - 7:26am — 9to5Mac Noob (not verified)

Two notes:

-Although I haven't tried it, I think we'll still have HDMI via cheap adapters. The new MB/MBP DOES do DVI, through the optional DP-DVI adapter. What happens there is the DVI signal is passed over the DP pins (optional in the DP spec, but supported by most DP chips). Since HDMI and DVI use the same video signal, any inexpensive DVI-HDMI adapter should work fine. I use one of these on my (now old) MBP frequently to show photos/videos on a Sony Bravia 1080p, works great. Audio needs to be run separately, but that's it.

The sad thing is the apparent loss of composite and S-Video out of the new laptops. Apple hasn't shown an adapter for these, so probably didn't do the work to make this happen internally. Yes it's old technology, but pretty much every TV has composite video.

-Someone asked about putting the new DP monitor on an older Mac. It isn't going to happen. DP and DVI are so wildly different, a little adapter isn't going to do it. As stated above the only reason we can get DVI out of the new laptops is the chipset recognizes the DP-DVI adapter and sends DVI signals instead of DP signals. Unless Apple built a DVI decoder into the monitor, that's a dead-end unless someone designs a true signal converter. Possible, but will probably be pricey. If Apple had a decoder in the thing, 1) they'd say it, and 2) it would be more expensive.

couldn't be...

Wed, 10/15/2008 - 10:14am — terry (not verified)

9to5Mac Noob wrote: "If Apple had a decoder in the thing, 1) they'd say it, and 2) it would be more expensive."

that monitor COULDN'T be any more expensive, could it? ;)

Converting hdmi's stream data

Wed, 10/15/2008 - 11:25am — toke (not verified)

Converting hdmi's stream data to dp's micropackets might get cheap after 100 million dp displays and graphics cards have been sold. Before that it will be expensive niche product.

A DisplayPort to HDMI

Wed, 10/15/2008 - 11:43am — 9to5Mac Noob (not verified)

A DisplayPort to HDMI converter already exists (http://www.startech.com/item/DP2HDMI-DisplayPort-to-HDMI-Cable-Adapter-C...). Because DisplayPort uses "packets" to transmit data between the source and display it seems that it shouldn't be to difficult to determine what pins on the mini DP map to the full DP and from there develop a miniDP to HDMI cable. I'm no rocket scientist but I can't imagine a converter couldn't be easily engineered.

This is no rocket science,

Wed, 10/15/2008 - 2:41pm — toke (not verified)

This is no rocket science, but packets don't convert to streams just by connecting the right wires...
dp2hdmi is easy because then GPU sends hdmi data through dp connector.

Converting hdmi2dp is the hard part, if and when the screen can't take in hdmi signal. If new ACD could, then it would have hdmi socket.

Talking about licensing fees is ridiculous; 4 cnets per product!

Glossy Screen?

Wed, 10/15/2008 - 2:41pm — Adrian (not verified)

I am on the fence about this change. Ordered the slick aluminum MacBook and a new sleevecase from sfbags.com. Can't wait.

Not sure about the ports either...time will see how adaptable I become.

Other display inquiry

Wed, 10/15/2008 - 7:39pm — Brad (not verified)

I'd just like to point out that at this time the only device capable of working with the new display is the macbook line, which comes with integrated webcam, the new apple display, also comes with a webcam, I realize that the next machines they put out will come with display adapters as well, however, it's only going to help the people that are hooking up their mac pro's and mac mini's (if they still exist to be transitioned to display adapter) so am I the only one that thinks this is a needless integration of technology, when Apple could have just out out a lower priced iSight with more green materials (reason they pulled the iSight to begin with was because it was not eco friendly)