If you only have 1 port on your videocard, you'll either need a TRUE splitter like the Matrox TripleHead2Go, or a different videocard. A standard splitter will only duplicate the signal. The TripleHead2Go will act as a true splitter, letting the OS/videocard know there is more resolution available than just one monitor. But I believe you'll need to use another monitor of the same resolution & refresh rate.... there's also a resolution limit on the TripleHead2Go, so you can't hook up 2x 24" monitors to it at 1920x1200 resolution each..