Why can't I set a resolution of 2560*1600 on my Dell Latitude e6320?

Question

I have:

• a 30" Apple cinema display, native resolution 2560*1600
• a Dell Latitude e6320
• an ePort+ docking station
• a displayport to dual-link DVI-D adaptor

The display has a dual-link DVI-D lead fused to the case.

The laptop has:

• intel HD 3000 graphics (known to support this resolution)
• a built in VGA port (useless)
• a built in mini-HDMI port (introduced with HDMI 1.3, and therefore capable of driving WQXGA?)
• Windows 7 32-bit
• The latest BIOS (A15)
• The latest graphics drivers from Dell

The docking station has:

• Two dual-link DVI-D ports
• Two displayport ports

I've tried both DVI ports and the both displayport ports with the adaptor and the best Windows will offer is 1280*800.

Hitting "list all modes" under graphics properties shows up to 1920*1080, but selecting it turns the display black until windows reverts to 1280*800.

The Intel graphics and media control panel has a custom resolution pane that lets you type in whatever you want. Inputting 2560*1600 gets you a "the custom resolution exceeds the maximum bandwidth capacity" unless you dial it down to 30Hz... which just gives a black display again.

Current theories are that despite offering Dual Link DVI ports the docking station doesn't actually wire them up as such... is that a thing that happens? The same would also go for the displayport-DVI dongle I have, mind, which seems improbable.

One avenue is looking for a mini-HDMI to DVI-D adaptor, though a brief search suggests these are rare and expensive.

On paper this should just work ;_;

Answer 1

I ordered an expensive active displayport-DVI adaptor off eBay and it works perfectly from the docking station's displayport.

I guess the apparent dual-link DVI ports on the Dell docking station and the Dell displayport dongle were both bogus. Despite having all the pins, they were wired up as single-link DVI ports.

Dell is terrible, is the take-away here.