Nvidia spent quite some time to explain to its investors and analysts why Hybrid SLI is a good thing. The company plans to unveil such a product this year.
It is a combination of IGP graphic and discrete graphic rendering together. The principle is rather simple. You take a graphics card, lets say an 8400 or an 8600 and plug it into the integrated graphic board and when you start playing 3D game the graphics card starts rendering together with the integrated graphics and ends up faster than the graphcis cards itself.
If you don’t play 3D graphic, the chipset can send your discrete graphics card into idle and save some power. AMD also talked about such a concept and this sounds like a great idea for notebooks.
According to Nvidia, if you plug an 8400 series graphic card into the board, you should get a significant performance increase, but this mode won’t give you a huge bump with an 8800 GTX, but it will be a few frames faster than without Hybrid SLI.