Not sure about Phi. But the code for CUDA works
1 - with simple isotropic dielectrics only. No anisotropy, or ferrite anisotropy is handled by GPU code.
2 - Non-enterprise GPUs are now artificially locked from execution. Even though Geforce supports all the CUDA capabilities of TESLA and Quadro, it was locked by some very dark(and forbidden even to guess) reasons from use.
3 - Only generations of nVidia Quadro and Tesla boards listed in the comptibility list are supported.
4 - Since ANSYS may lock non-listed Quadro and Tesla boards any time, despite the equivalence of CUDA capabilities with the listed boards, you have to consider purchasing exactly the boards from the list. Even if those are 10 times expensive and inferior to other boards on the market.... At least buy from the same series.
Not very nice, indeed. Particularly when comparing with the other software on the market.