On 18.07.2014 12:58, Dieter Nützel wrote: > Am 18.07.2014 05:07, schrieb Michel Dänzer: >> On 17.07.2014 19:09, Christian König wrote: >>> Am 17.07.2014 12:01, 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. > > Michel, > > please, please do NOT change anything on this!;-) > You all know that I currently can only run this on my poor Duron 1800 > with RV730 (AGP), but... > > With this all 'objview' demos (mesa-demos) run at 60 fps (vsync), > even with chip set/CPU power management enabled (athcool on). > > If I set vblank_mode=0 > the slowest GreatLakesBiplaneHP.obj > run at ~100 fps (~16 fps before) => 6x speedup. > (Even 5 planes run at 30 fps) - Wow!!! That's great, but note that the disputed change above only has an effect with SI or newer GPUs, i.e. none with yours. I suspect that speedup is because the app ends up using effectively static vertex/index buffers, which are now in VRAM instead of in GTT due to my Mesa changes. > Overall X/Kwin eXperience is much better. > Let me know which benchmarks you need. I'm not looking for anything in particular, basically anything where you care about performance. E.g. the usual suspects in PTS. > BTW Do anyone know how I can override BIOS GTT settings? > I can only set 256 MB max. - BIOS patching? Your AGP bridge hardware might not support more. > With agpmode=-1 I can run with 1024 MB GTT What effect does that have on performance? I'm not sure if AGP provides any benefit for GPUs with PCIe GART. -- 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
