@joel If you want commercially provided drivers for external cards, nvidia is the only game in town. But that's relying on the nvidia build for Solaris (it's some cross-compilation thing as I understand it) still working on illumos.
I'm more that happy with my old Intel HD integrated graphics with the default Xorg driver, full transparency and tear-free at 2560x1440. And the Intel integrated graphics is actually the only graphics that's really natively supported by illumos (via gfx-drm).