Having read Jeff Atwood's blog post on Korean 27" IPS LCDs, I've been wondering to what extent these are useful in a notebook + large display situation.

I own a Lenovo Thinkpad Edge E320 with 2nd gen. integrated Intel graphics. According to the spec from Intel, this should support HDMI version 1.4, and, using DisplayPort, resolutions up to 2560x1600. HDMI version 1.4 supports resolutions up to 4096×2160, however, according to c't (German), the HDMI interface used with Intel chips only supports 1920x1200. The same goes for the DVI output - dual-link DVI-D, apparently, is not supported by Intel.

It would appear that my laptop cannot digitally drive this kind of resolution. Now what about other laptops?

According to the article in c't above, AMD's integrated graphics chips have the same limitation as Intel's.

NVIDIA graphics cards, apparently, only offer resolutions up to 1900x1200 over HDMI out of the box, but it's possible, when using Linux at least, to trick the driver into enabling higher resolutions. Is this still true? What's the situation on Windows and OSX?

I found no information on whether discrete AMD chips support ultra-high resolutions over HDMI.

Owners of laptops with (Mini) DisplayPort / Thunderbolt won't have any issues with displays this large, but if you're planning to go for a display with dual-link DVI-D input only (like the Korean ones), you're going to need an adapter, which will set you back something like €70-€100 (since the protocols are incompatible).

The big question mark in this equation is VGA: a lot of laptops have it, and I don't see any reason to think this resolution is not supported by the hardware (an oft-quoted figure appears to be 2048x1536@75Hz, so 2560x1440@60Hz should be possible, right?), but are the drivers likely to cause problems?

Perhaps more critically, you'd need a VGA to dual-link DVI-D adapter that converts analog to digital signals. Do these exist? How good are they? How expensive are they? Is there a performance penalty involved?

Please correct me if I'm wrong on any points.

In summary, what are the requirements on a laptop to drive an external LCD at 2560x1440, in particular one that supports dual-link DVI-D only, and what tools and adapters can be used to lower the bar?