A DVI connector will probably not fit through a 3/4" conduit - if I remember correctly, the connector width is around 1-1/4" or so (EDIT: Had one on my desk, and it is 1-1/2" wide). Since DVI is rapidly thinning out on video gear, you probably won't be pulling one through. An HDMI connector (using the current design) is a good bit smaller than that, and would probably fit through that conduit assuming there wasn't much else already in there.