Hi Brecht, you're welcome ;) I think I'll have to include these compiler flag optimizations into vs2012 builds otherwise these builds will be significantly slower than other compilers :( Cycles has two problems when it comes to windows/vs2012 builds: 1. It is much slower on CPU 2. It is slower with cuda, if we don't use opt flags.
As long as MinGW OpenMP isn't fixed we have to stick to vs2008/cuda 4.2 or find a decent solution for VS2012/Cuda 5.5. As blender seems to be used mostly by windows users this isn't optimal. /Jürgen Am 03.06.2013 um 21:20 schrieb Brecht Van Lommel <[email protected]>: > Thanks for testing. I've also been doing some experimenting with > compile flags and other things here. So far it seems I can make my > 650M render a few percentages faster compared to CUDA 4.2, but 460 GT > is still considerably slower with the BMW scene (2m30s with 5.5 > compared to 2m01s with 4.2), and 580 GTX had a similar difference. It > seems you are testing with a 6xx card so that makes sense. > > Patch attached for those who want to test this with 5.0/5.5. > > On Mon, Jun 3, 2013 at 8:46 PM, Jürgen Herrmann <[email protected]> wrote: >> Hi there, >> >> >> >> I did some tests with cuda 5.0 and 5.5 today and changed the nvcc >> optimization flags for cycles_kernel_cuda. >> >> >> >> I found out the following: >> >> >> >> - “--opencc-options “ is deprecated for sm_20 and up and should be >> removed from compiler options >> >> - Stating “-O3” and “—use_fast_math” as nvcc options brings massive >> speedup on my system (more below) >> >> - We shouldn’t complain about new cuda toolsets that are slow, we >> should find a solution as we can’t use old software forever… >> >> >> >> To the speedups: >> >> >> >> Example 1: >> >> system: i7-3820 @ 3.60GHz, GeForce GTK 660 >> >> >> >> Blender (cycles_cuda_kernel) compiled with standard settings: >> >> Mike_pan file took 02:06.60 to render >> >> >> >> Blender (cycles_cuda_kernel) compiled with –O3 –use-fast-math: >> >> Mike_pan took 01:39:93 >> >> >> >> There is no optical difference in the render results: >> >> >> >> Image1: http://www.pasteall.org/pic/52757 >> >> Image2: http://www.pasteall.org/pic/52758 >> >> >> >> I bet there’s more potential in there. >> >> >> >> /Jürgen >> >> _______________________________________________ >> Bf-committers mailing list >> [email protected] >> http://lists.blender.org/mailman/listinfo/bf-committers > <cuda_5.5_tests.txt> > _______________________________________________ > 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
