In Unix word, and not only with Solaris, we have two choices with AMD GPUs. The first one is to use the manufacturer proprietary driver that is not free, but no Solaris driver exists.
The second solution, and this is what we provide, is to use the Xorg driver stack but without any (AMD) documentations the project provides drivers that are not very up-to-date and doesn't content all features.
as we are currently focused on nVidia and Intel GPUs because we can work with them, drivers for these both manufacturers give a much better results.
Which GPU model is installed in your laptop ?
CPU Type: AMD A6-4455M APU with Radeon(tm) HD Graphics CPU Number: 1 Number of cores per processor: 2 Number of threads per processor: 2
With most modern laptops you have either the choice between Intel Haswell or AMD A6 APUs.
Sure nVidia is great, but there are little pure nVidia chipsets around nowadays.
Most are hybrid Intel HD + nVidia chipsets.
Usually AMD CPUs make much less problems with Solaris 11.x (no matter what performance they have, it's just a laptop)
It a lot of models in the Radeon chip family that are not supported by the same driver version. Could you share tthe scanpci output or the Xorg.0.log file ?