My monitor is a 20" LCD @ 1200x1600, with a 1.8 meter cable. Just fine.
I ordered a 5 meter quality cable and received it by mail. First problem. The cable was pretty anonymously packaged in a plastic bag, with a sticker with just a product number. While the product number matched the manufactures number, I didn't feel sure if it was a genuine product, or just a fake copy, with a counterfeit sticker. The cable had no ferrites, though it should have.
Anyway, the image quality with the new cable was obviously degraded. Lots of shadows on icons on my desktop.
I concluded that I had buy it in a store, to make sure it looked like a genuine product, so I went to a store and bought a 3 meter quality cable with ferrites, and went home to try it.
It seemed OK, but closer inspection revealed some color issues in the corners of the screen. Also when i loaded a game in 640x480, there were a kind of fuzziness in the image, mostly visible in the menus.
Another problem. The two cables i tried was missing a power safe connection, so the screen no longer turned off during power save, but kept showing a "no signal" message. A little annoying, and impossible to know before purchase.
I conclude that a modern system can't be moved to another room, unless it is just on the other side of the wall, which in most cases is impossible.
