The documentation from Dell and others is utterly atrocious, so people like me write posts like this to help others with their setup. First, although Dell never documents this, these are the limits for various kinds of input:
- DisplayPort can do the full 2560x2048
- DVI-I Dual Link can do the full 2560x2048
- VGA can only do up to 2048x1152. (Interpolation makes text a bit fuzzy.)
- DVI Single Link can do up to 2048x1152
- HDMI I can't test properly.
Then there are the variations of support by various systems. Vendors do not document their hardware well enough to know what will work without trying it. I have found:
- MacBook Pro with MacOS, DVI-I Dual Link is supported at full resolution
- Intel D94GZIS with Windows 7, DVI-single link at 1600x1200, DVI-VGA Adapter at 2048x1152
- Intel DH67CL with Linux and Intel Driver 2011Q3, VGA adapter to DVI works at 2048x1152, DVI only up to 1600x1200
- Dell Latitude 630 in Docking Station: DisplayPort at full resolution
The documentation and connector for the DH67CL claim dual link capability but after various experiments I've found no way to configure the driver to use it properly. Documentation of the Intel driver provides no information about dual link setup. The default configuration did not set it up automatically.