New MacBooks can manage many, many monitors

2012 Air supports two external displays; the Retina MacBook Pro supports three.

The 2012 MacBook Air is dwarfed by the two external Thunderbolt Displays it can drive. Credit: Gabor Cselle via 9to5Mac

Users of multi-monitor setups are in for a treat: according to a report by 9to5Mac and legwork by Gabor Cselle and OWC, the 2012 MacBook Air can support two external displays for a total of three, while the Retina MacBook Pro supports three external displays for a total of four. Past MacBook Airs have only supported the use of two displays simultaneously, while the 15″ and 17″ 2011 MacBook Pros could only support a total of three.

The number of displays that Thunderbolt-equipped Macs can drive is dependent largely on the capabilities of the GPU and the Thunderbolt controller chip installed. The Intel HD Graphics 4000 GPU in the 2012 MacBook Air supports a total of three displays (up from the two supported by last year’s HD Graphics 3000) and the Thunderbolt controller used by both the Air and the Retina MacBook Pro, the DSL3510L, also supports two display outputs. Because the Air only has one physical Thunderbolt port, however, the only way to support the maximum number of monitors is to daisy-chain Thunderbolt displays—an expensive proposition.

The Retina MacBook Pro, on the other hand, sports two physical Thunderbolt ports plus an HDMI port, meaning that you don’t need to do any daisy-chaining to get to the maximum of four displays that the more powerful NVIDIA GeForce GT 650M is capable of pushing.

While no one spent any time talking about the capabilities of the non-Retina MacBook Pros, the fact that they both share so much hardware with their thinner cousins makes conclusions easy to extrapolate. Since the 13″ MacBook Pro uses the same Intel HD Graphics 4000, DSL3510L Thunderbolt controller, and single physical Thunderbolt port as the new MacBook Air, it should be able to push a total of three monitors using daisy-chained Thunderbolt Displays. The 15″ MacBook Pro, on the other hand, uses the same graphics and Thunderbolt hardware as its Retina Display cousin but lacks an HDMI port. This means that it is likewise capped at three displays, making it the only model that supports the same number of monitors as its 2011 counterpart.