Is 3D Acceleration supported?
Using multiple and/or dual-headed graphic cards in Linux prevents software that uses 3D acceleration (i.e., some game software) from functioning properly. This is not a 1-Box specific issue, but rather a known issue with Direct Rendering Infrastructure (DRI) within the current X-server system. XFree does not support DRI acceleration on multiple graphic cards. XFree extensions not dependent on DRI should work, for example 2D acceleration is supported.