Electrically these are *almost* the same signal, but with different connectors. The issues regarding cable length are the same for both types of signal.
Long Cables
A long cable is the simplest and most reliable means of extending an HDMI or DVI signal – so long as the cable is up to it! The quality of the cable becomes more important as the cable length and the resolution are increased. You can achieve up to a 15m run with a good quality cable, slightly longer at lower resolutions. It is important to use a reputable cable manufacturer to get predictable results.