Let me try to explain the current situation: The main missing feature is float3 support, though we found now that for ATI/apple, there seems to be a bug in their 1.1 drivers related to that, and we found a trick to avoid using it yesterday. That might help getting things working on older ATI's, but again, their driver currently can't even compile the full kernel. I'd love to have Cycles running on any GPU and have spent weeks working on OpenCL/ATI support, but progress is slow.
We don't want to be biased towards NVidia, but they've got one major hardware/compiler advantage, which is that not all functions need to be inlined. Without this every feature that is added puts more stress on the compiler, making it crash or run out of memory. With the next AMD driver release (which includes a bugfix they did for us), it looks like we'll be able to support basic path tracing, but without transparent shadows, improved closure sampling and procedural textures. Probably that will be in 2.62. The only other GPU raytracer with ATI support (that I know of and isn't a research prototype) is SmallLuxGPU, and they are also limited in features and fighting compiler issues. V-Ray RT (OpenCL), Octane, Arion and iRay (CUDA) are all NVidia only still. Brecht. On Thu, Dec 8, 2011 at 12:43 PM, Antony Riakiotakis <[email protected]> wrote: > On 8 December 2011 13:06, Thomas Dinges <[email protected]> wrote: >> Well, I don't think we need to discuss that. AMD 4xxx cards were not >> designed for OpenCL, the support was added later via driver. It's the same >> on nvidia, the Femi cards were the first, designed for CUDA. >> >> The fault is therefore not on our side and discussions won't solve it. ;) >> > > This is hardly a good reply. Of course OpenCL support is added through > the driver, hardware simply executes opcodes. The support was added > after all, so people still expect to be able to use it. A discussion > will make people understand so it solves any suspicions of bias. My > understanding is that certain features or extensions either run on > software or are missing. If people can know them though, and know > their importance they can be more understanding. And more importantly, > they can stop feeling that the developers are biased towards NVIDIA. > > Anyways, here are some references: > > http://developer.amd.com/sdks/AMDAPPSDK/pages/DriverCompatibility.aspx, > where you can clearly see that GPUs have beta OpenCL support > (unfortunately couldn't find the conformance results) > > http://developer.amd.com/sdks/AMDAPPSDK/assets/AMD_Accelerated_Parallel_Processing_OpenCL_Programming_Guide.pdf, > where, if you check under AppendixD the lowest GPUs mentioned are > series 5. > > http://developer.amd.com/sdks/AMDAPPSDK/assets/AMD_APP_SDK_Getting_Started_Guide_v2.4.pdf > check section 5 supported devices, where all the features supported > are enumerated. > _______________________________________________ > Bf-committers mailing list > [email protected] > http://lists.blender.org/mailman/listinfo/bf-committers _______________________________________________ Bf-committers mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-committers
