Triple Headed Desktop Display for Fast 3D Apps?

Once Was SGI Customer asks: "My group was once a big SGI user. We run a Powerwall display center with 3 large screens, currently driven by an SGI Onyx Infinite Reality (IR) to provide a single desktop with 3D acceleration across all screens. The Onyx is now old and very slow compared to our Nvidia cards, that do a great job at TwinView display, but not 'TripleView'. I'd like to know if there are any PC manufacturers who make a card that can do what the IR can do (in terms of a single desktop across 3D displays with fast 3D acceleration), but for Windows and Red Hat (now Fedora Core) Linux?"