Multi GPU performance and gaming has always been something of a mystery as well as a game of hit and miss. Many times you will not see a significant performance increase when you drop in the second GPU, while others may yield excellent results. It is one of those things that either works; or it doesn't. And that is just SLI and Crossfire. When we throw Fuzion into the gaming mix we find things are even more complicated.
Fuzion adds another level of complexity to the game. It is fighting systems that are already in place in addition to drivers that may be working against the system. With the AMD GPUs we saw the system try and enable Crossfire until the Fuzion driver took over. A Similar thing happened with PhysX and the NVIDIA pair. MSI and Lucid have a lot of work to do on the Fuzion drivers to make them work better under the stress of real world gaming. They have many of the benchmarks down (3DMark Vantage works well), but let's face it; not all of us buy a board to run 3DMark.
We will be working with MSI to see where the root causes of this are and if there is a simple and effective way to get around the gaming issues we saw here. For now, it is very cool to get dual NVIDIA GPUs working together on the 870A Fuzion. Now they just need to get it to work right.