[citation][nom]alidan[/nom]id still rather have an open solution to cuda than cuda... nvidia has wronged me in the past and i will never for give them...[/citation]
They haven't personally wronged you, Alidan. Quit your crying.
There already are several open solutions. OpenCL for one is coming along nicely. But this requires that the hardware manufacturers meet THEIR specs. With CUDA, the software meets Nvidia's specs.
There are simply things OpenCL cannot do that CUDA can. And OpenCL is excellent of course, but AMD cards and Nvidia cards are simply built differently. It's apples and oranges, when it comes to GPU compute performance. Gaming it would be apples and apples, but raw computations are a different monster...
If you've ever used iRay (mental images) or Vray-RT for GPU rendering, you'd know the difference. Since you haven't, it'll give you a point to research.