On 19.07.2014 00:47, Christian König wrote: > Am 18.07.2014 05:07, schrieb Michel Dänzer: >>>> [PATCH 5/5] drm/radeon: Use VRAM for indirect buffers on >= SI >>> I'm still not very keen with this change since I still don't understand >>> the reason why it's faster than with GTT. Definitely needs more testing >>> on a wider range of systems. >> Sure. If anyone wants to give this patch a spin and see if they can >> measure any performance difference, good or bad, that would be >> interesting. >> >>> Maybe limit it to APUs for now? >> But IIRC, CPU writes to VRAM vs. write-combined GTT are actually an even >> bigger win with dedicated GPUs than with the Kaveri built-in GPU on my >> system. I suspect it may depend on the bandwidth available for PCIe vs. >> system memory though. > > I've made a few tests today with the kernel part of the patches running > Xonotic on Ultra in 1920 x 1080. > > Without any patches I get around ~47.0fps on average with my dedicated > HD7870. > > Adding only "drm/radeon: Use write-combined CPU mappings of rings and > IBs on >= SI" and that goes down to ~45.3fps. > > Adding on to off that "drm/radeon: Use VRAM for indirect buffers on >= > SI" and the frame rate goes down to ~27.74fps. Hmm, looks like I'll need to do more benchmarking of 3D workloads as well. Alex, given those numbers, it's probably best if you remove the "Use write-combined CPU mappings of rings and IBs on >= SI" change from your tree as well for now. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
