You know that you don't need the crossfire bridge for mining right?
Unless he's running Windows and doesn't have or want to use dummy plugs.
Crossfire hurts your performance when mining. People use dummy plugs because they have no choice. When I had 4x crossfired it was constant problems.
I had no issues with performance. I used it because its easier than using dummy plugs and works just fine. I do my testing under windows which forces me to use those cables. Plus it looks much nicer and allows the person to have a high end gaming pc along with a great miner. Plus the bridges dont cost me anything, i wa getting 400mhahes/s from each card at 900core. Was it suppose to be higher?
My 4 dummy plugs cost me around $2. But yes crossfire is cheaper. =)
Crossfire can cause problems, which is why it's suggested you disable it. People aren't making dummy plugs for the looks, it's out of necessity. But if you can crossfire and you don't have any problems more power to you. I went crossfire to start because I didn't want to make dummy plugs. Had a lot of issues and had no choice but to go the dummy plug route.
Regardless very nice rig. =)