NVidia has unveiled technology that enables two GeForce 6 Series or Quadro graphics cards to operate in PCI Express-based PCs and workstations.

While Apple uses both NVidia and ATI graphics systems, it does not support PCI Express, nor has it given any indication that it plans to.

According to NVidia, the patent-pending NVidia SLI technology features an "intelligent communication protocol embedded in the GPU and a high-speed digital interface on the graphics board to facilitate data flow".

It adds: "A complete suite of software provides dynamic load balancing, and advanced rendering and compositing to ensure smooth frame rates and outstanding image quality."

NVidia marketing executive vice president Dan Vivoli said: "There is a category of NVidia users that will always demand even more extreme graphics performance than what our industry leading solutions currently provide.

"We share their passion for jaw-dropping graphics performance, so we created SLI, an innovative new multi-GPU approach. The result is never-before-seen performance on PCs and workstations."