interessante analyse de appleinsider a propos du displayport
The mini DisplayPort catch-22
Mini DisplayPort also allows even the entry level MacBook to support the 2560x1600 resolution of Apple's most expensive 30" Cinema Display without needing the large, 24-pin connector demanded by dual-link DVI on the relatively small notebook. The muscle to drive that resolution is provided by NVIDIA's 9400M controller chip; the previous MacBook, using integrated Intel graphics, lacked the capacity to drive a 30" resolution display despite having a DVI connector with the pins available. Resolutions lower than 30" only require single-link DVI, which uses 6 fewer pins on the DVI port, although the connector itself is the same size.
The new MacBooks now have the best of both worlds: a small connector and the capacity to handle very high resolution. Somewhat ironically, the converter for adapting the MacBook's Mini DisplayPort for use with the dual-link DVI signal required by the 30" Cinema Display not only costs $99, but it's not even available for purchase yet.
Dell makes a 30" monitor of its own that uses DisplayPort, although the "Mini DisplayPort" used by Apple isn't common (it appears Apple invented it) and therefore cables aren't yet readily available to connect the new MacBooks to a third party, full size DisplayPort-equipped screen either. Apple's
new 24" LED Cinema Display uses Mini DisplayPort exclusively, so it can only be used by the new MacBook and MacBook Pro. There are no converter boxes for turning DVI signals from a Mac mini or Mac Pro into DisplayPort, which uses not just different physical wiring but an entirely different signaling protocol.
In other words, during the transition from DVI-based Macs to DisplayPort, there are a number of things that won't work together. From this point forward, all new Macs will have DisplayPort (likely Apple's Mini variant, as there is no obvious advantage to using the larger version), and new Cinema Displays will also eventually gain the new connector. Existing 30" displays will require a somewhat expensive box (although if you can afford a 30" screen, you're probably not sweating over a $99 converter), but other displays only need the $30 VGA or single-link DVI dongle to work with a new mini DisplayPort Mac.
The Apple TV will likely retain HDMI rather than mini DisplayPort, as it doesn't need to drive display resolutions higher than HDTV's 1920x1080, which HDMI has no problem doing. DisplayPort is only required for driving higher resolution monitors with 30" 2560x1600 resolutions or greater.
donc a moins qu'un fabricant sorte un boitier de conversion du signal, et sans doute couteux, Apple a bien verrouille l'utilisation du mini displayport pour pousser les gens a acheter la derniere gamme de machines...
ils auraient peut etre interet a sortir rapidement leurs propres adaptateurs pour permettre aux mac users existants de brancher mac mini, mac pro et precedents laptops