A very small portion of the NV40 GPU (~0.75% of die area) is
allocated to offer SLI capability and a few pin-outs from the 40x40mm FCBGA
(flip-chip ball grid array) package are actually SLI pins. Interestingly, David
Kirk told us that the SLI scalability allows up to 8 GPUs.
The graphics workload is dynamically balanced between the two
graphics cards through their patent pending load balancing algorithms. One of
the cards will be Master if it is on the slot with x16 bandwidth while the other
as slave and the video signal is output from the Master card to a monitor. The
upcoming Forceware drivers will be able to support SLI seamlessly and no games
patches needed nor image quality will be sacrificed.