Michel Dänzer wrote: > On Sat, 2009-04-18 at 13:46 +0800, Michael Clark wrote: > >> I have made a port of gears that uses the OpenGL ES 1.1 Common API >> subset (using glDrawElements instead of display lists and optionally >> using vertex buffer objects). It should be visually equivalent to >> gears.c, although the flat faces are rendered with GL_SMOOTH to avoid >> additional draw calls. >> >> While testing it, I noticed a severe screen corruption issue when using >> vertex buffer objects with the intel driver in ubuntu (both ubuntu 9.04 >> driver and ubuntu xorg-edgers 2.6.99.1+git20090416). I have verified the >> code is working with the nvidia-180 proprietary driver on another system >> so I believe it is an intel driver issue. I am wondering if the same >> issue exists upstream... >> >> The attached gearsvbo.c source code can be compiled with: >> >> gcc gearsvbo.c -o gearsvbo -lGL -lglut >> >> It can be run with or without vertex buffer objects (add -novbo command >> line option to disable). >> >> With the Intel driver I see a 40% speedup with glDrawElements alone. >> With vertex buffer objects enabled I see almost 200% speedup although >> the front-buffer doesn't appear to being cleared or swapped correctly >> (see attached png). >> > > Fixed in Git. >
Thanks. I just noticed the fix has arrived in ubuntu xorg-edgers as of mesa_7.4.1~git20090420+mesa-7-4-branch. Before trying this I built from mesa master earlier today and noticed a performance regression with the 965GM on one of my GL apps - going from 15fps to 7.5fps (both running on top of latest drm-intel 2.6.30-rc2). 7.4.1 doesn't exhibit the slow down. It seemed to be a timing issue as the app would no longer be using all cpu of a single core (noticeably less cpu than on the 7.4-branch version), and paradoxically, running another cpu intensive task would result in the fps increasing. I'll do some more testing (and double check the two builds were configured equivalently)... BTW these were both with ubuntu's dont_vblank patch applied. ~mc ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
