Although Scalable Link Interface and Crossfire operate on the original SLI principle, the algorithms used are now totally different.

SMs have Dual Link Interface (DLI) cards to connect them by multi-mode optical fibers to the Communications Modules for time-divided switching to other SMs.

Having since acquired 3dfx, Nvidia in 2004 reintroduced the SLI brand (initially called Scalable Link Interface) in the GeForce 6 Series.

It is also possible to use multiple GPUs in a single computer, using technologies such as NVidia's Scalable Link Interface and ATI's CrossFire.

Scalable Link Interface (SLI)

The Scalable Link Interface (SLI) allows two GeForce 6 cards of the same type to be connected in tandem.

The SLI trademark passed to Nvidia upon its acquisition of 3dfx in 2000 and now stands for Scalable Link Interface.

Scalable Link Interface (SLI) is a brand name for a multi-GPU solution developed by NVIDIA for linking two or more video cards together to produce a single output.

It also implemented high dynamic range imaging and introduced SLI (Scalable Link Interface) and PureVideo capability (integrated DVD Video decoder, eliminates the need for software video decoders).

The SLI version has all the features of the Ultra version, in addition to SLI (Scalable Link Interface).