Many users, during the launch of the MacBook Pro Retina when it was announced that it had two Thunderbolt ports in addition to its HDMI, they must have thought if it could actually support four screens (3 + the notebook). Maybe it’s a bit much for some, but many others would have been drooling. The answer will make them drool even more: yes, it can support four screens simultaneously.
The guys from The Verge connected two 1080p displays through a DVI to Mini DisplayPort and one monitor with a resolution of 1600×900 pixels via a HDMI port. Within a few seconds each of the screens showed that galaxy screen that is so beautiful as the wallpaper of Mac OS X Lion while the Retina screen provided a resolution of 2880×1800. This means that the laptop is pushing a total of 10.7 million pixels when the three monitors are connected.
When they had everything connected they began to play with it. They executed applications like Safari, IRC, Twitter, Lightroom and Photoshop and moved it across all the different monitors and, surprisingly, it worked perfectly. They pushed for more and loaded a 4K video, pressed play and began to move it through the different screens while playing. Again, everything worked smoothly.
There are limits, of course. When loaded four different videos (4K each) and played them using the NVIDIA GT 650M it began to suffer. Its interesting however to see what the MacBook Pro Retina can do.