Not just gaming but GPGPU. It's really popular to stick NVidia compute cards (which are pretty much just their GPU's) into a Linux cluster. AMD tries to offer similar lineup with their FirePro server cards but in practice they're insanely annoying to use, and nowhere near as fast as what NV is offering mostly due to driver issues. As an example: They only recently released drivers that allow you to use OpenCL on them without having X running. NVidia has offered same feature for years and years.