Towards hiDPI screens: Is the maximum resolution listed on a graphics card absolute?

[FrenchKheldar]

I have an aging video card in my Mac Pro (GT120) and my trustful Dell 2407WP just died after moving (although I hope to repair it). Looking at newer video cards and getting excited about large (24"+) hiDPI screens (in 2013?), I noticed that most of them list WQXGA 2560x1600 as the maximum supported resolution. I have a hard time believing this is a technical issue given that 1. one can drive 2 monitors of said resolution with a given card (I know there are bandwidth issues but I'm not clear on them) 2. the mobile graphics inside the retina MacBook Pro drive higher resolutions than WQXGA. If I'm buying a card today (say the GTX660) with a supposed max resolution of 2560x1600, what are the chances that it could drive an hypothetical hiDPI display of 3840x2400 (upper limit for Display Port according to wikipedia)? Would it just need new driver? Will this only be possible using thunderbolt/DisplayPort connection and not DVI?

Technical issues aside, is this kind of silly? Is such a hi-res screen going to cost $1500+ and require a better card than the GTX660 to get good performance? My uses would be digital photography (Aperture) and moderate gaming (blizzard games). Should I just go with the GTX660 (less than $250) and a Dell 27" for $650, already a nice upgrade compared to what I'm used to? Thanks in advance !

Full disclosure, this a double post from SuperUser in case you guys/gals are interested...

 

[Librarian580]

If there is a limit on resolution for something, it would likely come from the type of communication port itself. HDMI and Single-link DVI for example are limited by the port, possibly by the firmware of the card.

However, it would not be the drivers nor the card itself. An example is Dual-link DVI, which has a "theoretically infinite" resolution limit, but at the cost of refresh rate.
Example of such a monitor that can actually be found:
http://en.wikipedia.org/wiki/IBM_T220/T221_LCD_monitors

 

[All Taken]

If there is a limit on resolution for something, it would likely come from the type of communication port itself. HDMI and Single-link DVI for example are limited by the port, possibly by the firmware of the card.

However, it would not be the drivers nor the card itself. An example is Dual-link DVI, which has a "theoretically infinite" resolution limit, but at the cost of refresh rate.
Example of such a monitor that can actually be found:
http://en.wikipedia.org/wiki/IBM_T220/T221_LCD_monitors

With HDMI 1.3a or 1.4 I forget which, support for resolutions up to 4K was introduced. Surely if it is the connectors governing the output then the specifications of the card should be support up to 4K?