You can find more details about recommended hardware on Help Center. You can find a list of recommended graphics cards at:
Hard disk space: 5 GB free disk space is required for the installation, 10 GB or more is required per active project.RAM: 4 GB or more is recommended, for complex, detailed models 8 GB or more may be required.Processor: 64-bit processor with two or more cores.Hardware for BIMx Desktop Viewer Recommended hardware Windows XP (32-bit and 64-bit) is not compatible.Windows Vista (32-bit and 64-bit) is not compatible.Mac OS X 10.6 Snow Leopard is not compatible.Mac OS X 10.7 Lion is compatible but not tested by Graphisoft.
Operating Systems for BIMx Desktop Viewer Recommended Operating Systems