Eric Anholt wrote: > We're getting close to ready to mark GEM on Intel as done. We've got > one failing testcase that we isolated this week with interrupt handling, > and we've got a fix in testing that appears to be doing the job. > > Tomorrow I'm planning on merging the GEM code to master of all 3 > repositories. At that point, I'll cut a branch called drm-ttm in drm > with the existing interface and support. After that I'm planning on the > following changes: > > 1) Remove TTM code from i915. > We're going forward with GEM and not going to support two memory > managers in our driver. GEM's got the features we need and equivalent > performance, with a simpler implementation. > This is going to hurt badly, since IMHO the GEM implementation is quite far from TTM in terms of performance and stability: Again some benchmarks with a i915 dual-channel 3GHz celeron. I've also, for reference added in timings of a (polling only) CX700 Via C7 at 1.5GHz running single-channel on untiled memory. In all of these timings, reportdamage was turned off since with it, the X server tends to consume a lot of CPU, confusing the figures somewhat.
*GEARS* (Should be GPU bound) i915tex (TTM): 1035fps @ 70% CPU GEM, no buffer reuse: 863fps @ 95% CPU GEM, buffer reuse: 1000fps @ 80% CPU Unichrome CX700 1009fps @ 70% CPU *Openarena +exec anholt @640x480* (Should be GPU bound. Not on the CX700, though). i915tex (TTM): 48fps, 17.1user, 2.6 system GEM, no buffer reuse 30.4fps, 17.0 user, 8.0 system (Occasional stutter) GEM, buffer reuse 42.5fps, 16.0 user, 4.7 system (Occasional stutter) Unichrome CX700 24.5fps, 39.0 user, 3.0 system *"Ipers" without help screen to avoid sw rendering:* (CPU bound) i915tex (TTM): 250000 polys / s. GEM, no buffer reuse 141000 polys / s. (Severe text rendering errors) GEM, buffer reuse 146000 polys / s. (Severe text rendering errors) Unichrome CX700 205000 polys /s. *"Teapot" without help screen to avoid sw rendering:* (Might be GPU bound on i915tex, CPU-bound on others) i915tex (TTM): 74 fps GEM, no buffer reuse: 23.8 fps (Severe text rendering errors) GEM, buffer reuse 24.5 fps (Severe text rendering errors) Unichrome CX700 36 fps *"texdown" processor -> GPU transfer benchmark. Teximage and texsubimage.* i915tex (TTM): 1360 MB /s, 970 MB /s GEM, no buffer reuse: 556 MB / s, 138 MB/s (Severe text rendering errors) GEM, buffer reuse: 556 MB / s, 139 MB/s (Severe text rendering errors) Unichrome CX700 690 MB / s. 658 MB / s. I guess these benchmarks speak for themselves. Obviously, with more GPU bound applications, the various Intel flavours should perform quite equal, as long as the GPU is continously fed new data. Apart from the span rendering problems above, the "subtexrate" test rendered very incorrectly with GEM and the X server died on multiple occasions when doing quick "konsole" scrolling. The text rendering errors were not seen on a i945 laptop. My humble suggestion is that these performance-, rendering and stability problems are addressed before a merge. /Thomas ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
