I just purchased a Dell U2412M monitor for photo editing. It came with a 6 foot DVI-D (18 pins +1) single link cable for connecting to my computer graphics card. It is too short for my set-up, but I can only find dual link DVI-DD(24pin) cables at 10 feet long. It seems like the unused pins which are missing on the original cable, and I suppose not connected to anything on the monitor, should not be an issue, but I am looking for some experienced users for confirmation on the substitution. Can the dual link D cable be substituted for this use?
You can always use a dual-link cable instead of a single-link cable, but it will be thicker and usually more expensive. Consider the dual if you plan to upgrade to a higher res monitor later on. monoprice.com should have plenty of cables for your needs.
Dont worry, with dual DVI your computer will automatically show the highest res possible, but you dont have to stick with that. As others have stated before though - they are a bit more expensive. If your monitor supports dual DVI, then get it, even if your computer doesnt for future upgrades.
Monoprice for the win, no question about it.
If your monitor and computer support displayport, or mini displayport ( apple mbp ) I second the motion to go that route.