Yes, extension cables will degrade the signal. All Video cables are in fact electromagnetically shielded, and most wont have any problems with that ~3-5ft that comes attached to your monitor (unless you have some strong magnetic fields near that cable). However once you start adding more cable than that, you are inviting some fuzziness and other not so fun visual qualities. I personally run from my radeon 64 through an old v2. After reading your post I decided I would check visual quality w/ and w/o the passthrough. The verdict is, if my eyes havent failed me, that I can see a few more subtle nuances in my wallpaper with the direct connection (its a 32bit work of art I swear . Anyway, before my current set up, my tower was 10 feet away from my monitor (rather inconvienient), so I have had first hand experience with monitor extensions. First of all, you NEED the heavily shielded one. Secondly, they are VERY expensive. My local CompUSA wanted 45$-60$ for a 6 foot extension and even more for the 10-12 footer i really desired, so I bought a cheap brand X one for 35$ from a local computer show. The difference between direct connect and extension is very obvious. With the extender I had about 6 evenly spaced 2mm wide vertical dark areas in my display, and the picture was fuzzy. Very fuzzy. I could still read the desktop icon text, but it bordered on being annoyingly hard to read. So yes, passthroughs will mess up your display some but its the extentions that REALLY get you.