Please help! I have a simple question that the Apple Genius who were not able to answer accurately.
_*What is the maximum resolution of an external monitor that can be attached to the new MacBook Pro??? What is the maximum output resolution? I need some numbers.*_
I just got the following response: +"It should work. You can attach a monitor with resolution no matter how great only if an Apple display".+
In the section
below the Display info about the built-in screen:
"Graphics and video support
Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and *up to 2560 by 1600* pixels on an external display, both at millions of colors."
Note that if you are using the *Mirror mode* (which is the default setting), both screens will be the same, with the same resolution. For example, if the computer is the MacBook Pro 17" with a native resolution of 1920 x 1200 and you are using 's external Cinema 24" Display whose resolution is also 1920 x 1200, then no problem.
However, if, you are using the same computer with, say, 's 30" Cinema HD screen (2560 x 1600 native) and both screens are turned on ( *Mirror setting* ), then both screens should be 1920 x 1200 by default, and both will look good; but if you turn up the resolution of the external screen to 2560 x 1600, then the picture on the external screen will be slightly fuzzy.
In order to have the external screen not be fuzzy when set at 2560 x 1600, you need to use the *Extended Desktop mode* (instead of Mirroring). This can be set in System Preferences > Displays (you see this choice only when the second display is connected to the computer).