With the introduction of the new gorgeous “unibody” all aluminum 13″ and 15″ MacBooks, Apple made the move to DisplayPort in favour of DVI. What gives?
Despite the generic sounding name, DisplayPort is a new standardized connector and protocol designed to connect computers to digital displays. It was developed by VESA, a group of companies working on defining various display-related technologies since the Super VGA era in the 80s.
In many respects, DisplayPort is a competitive technology to DVI and HDMI. The DisplayPort group claims various technical advantages over DVI, such as the protocol being packet based (similar to the TCP/IP protocol that is driving the Internet and most other networks), it is scalable so that it can be enhanced in the future without breaking compatibility, and it can daisy-chain multiple displays over 1 connector at the computer’s end. Most importantly, they claim lower cost, due to the lack of a step-in fee (like the $10,000 required for HDMI). And because of technical reasons that go beyond the scope of this blog and certainly my technical expertise, it requires less components in a display monitor, as the digital video format can be sent directly to the LCD panel, further reducing cost.
However, most of these improvements are bearly real advantages to general users, and I expect more political reasons to be the real motivator fot its supporters to push this standard over the DVI and HDMI conntectors. A different share of the IP fees and licensing are more likely reasons.
What does this all mean for the consumer? Well, for starters it is yet another connector bus, meaning new cables and connectors. DisplayPort connectors on a computer can optionally carry a DVI (and even VGA) signal as well, officially called Multimode by the DisplayPort group. This means that by attaching a suitable adapter (which might be a bit expansive, as some voltage level adjustment is needed to convert the signal), you can connect such a Multimode DisplayPort connector to your standard DVI, HDMI or VGA display. Thankfully, the new Apple notebooks offer such a port, so that you can still use your existing displays. Note however, that Multimode is not required by the spec, so some DisplayPort computers cannot be connected to non-DisplayPort monitors. Due to the higher bandwith of DisplayPort compared to DVI and by using the slightly more expansive adapter cable, all of the new MacBooks (including the 13″) can now even drive dual-link DVI displays, such as Apple’s big 30″ Cinema Display, up to 2560×1600 resolutions. Apple sells all the adapters.
Another thing to bear in mind is that such a converting adapter can be used to connect a DisplayPort computer to a non-DisplayPort display, but that such adapter are not available the other way around, as far as I could find out. This means that Apple’s new 24″ LED Cinema Display can not be connected to any of its computers other than the new 13″ and 15″ MacBooks, and this November’s new MacBook Air. I’m sure this will generate a lot of confusion, especially since Apple is not clearly stating this lack of legacy compatibility on its web site. I do think however that all of Apple’s computers (including the iMac, Mac Pro and whatever will finally succeed the aging Mac mini) will move over to DisplayPort in the near future.
And finally, it is worthy to note that Apple is using a conector they dubbed Mini DisplayPort. This is different from the standard DisplayPort connectors that are being advocated by VESA. For now, it is unclear whether this Mini variant is an Apple propetary option, or a format proposed by the DisplayPort group. In the past, the Mini DVI and Micro DVI ports (the latter of which only ever was used on the first generation MacBook Air) were also Apple inventions, and required an adapter to connect to a standard DVI port.
Let’s hope that DisplayPort will eventually be worth the hassle of introducing yet another connection method, that is only partly compatible with older equipment, and which will for sure generate a lot of confusion in the market place. Some manufacturer’s are also jumping on the DisplayPort bandwagon, including Dell, Lenovo and Nvidia, but by completely replacing the former connectors with this new one on all of its new laptops, Apple is making the boldest move. Then again, Apple has done things like this before, like abandoning serial, parallel and SCSI ports in favour of that new standard called USB when they introduced the first iMac in 1998. And we know how the popularity of that connection method eventually turned out.
Update December 1, 2008: Mini DisplayPort indeed seems to be an Apple development, however the company has announced that they will license the specification for free to other manufacturers willing to incorporate it into their products.