Hi All, Wow no comment on my trying out ATI under linux... hell freezing over moment seems to have gone unnoticed...
Still lets have another bash at waking your up... With the addition of a ATI card here I now have coverage of ATI (Red), > NVidia (Green) but as yet no Intel (Blue) parts. The later will require > buying a motherboard that has Intel onboard graphics, or patience as I'd > have to wait for Larabee to come out... > Yesterday a new motherboard arrived in the post that I purchased with the intent of testing out Intel integrated graphics. The board is an ASUS P5Q-EM with G45 chipset and Intel GMA X4500HD. This board replaces my heavy duty triple 16xPCI Express motherboard that hosted my first Quad core processor, while the new card only has a single 16xPCI Express slot, it is for the most part capable of handling all the memory, devices and the quad core that I need for my second dev station. My initial attempt at using the Kubuntu 9.04 beta Live CD and the onboard graphics was a failure as intel graphics drivers that it came with screwed up all desktop rendering leaving me with just a black or a pinstripped desktop. Throwing in a NVidia graphics card and then re-running the the Live CD worked fine so using this I was able to install Kubuntu 9.04 beta and once the OS was installed an update pulled in improved Intel drivers, or at least that what I was hoping... So hoping for the best I pulled out the NVidia grpahics card and configured the bios to use the onboard graphics, then rebooted and waited with bated breath... would it work... would it fail.... Less than a miniute later Kunbuntu booted to the desktop no problems, enabling desktop effects even worked - these use OpenGL compositing. So far so good, the open source Intel drivers were providing a better out of the box experience than the ATI propritary drivers w.r.t KDE and desktop effects as the my ATI machine still is really flaky w.r.t initializing desktop effects. Performance with the composited desktop is also very good, can't really tell the difference between NVidia, ATI and Intel when just using the desktop - they all just work smoothly. Next up it was time to get the OSG compiling, once the mesa glx and glu headers/libs were installed everything built without a hitch. Running through the examples almost everyting works, even the shaders. Fill rate/shader performance is actually far better than I expected, and the onboard graphics can handle the glsl_mandelbrot.osg dataset very well. Things aren't prefect though. No Texture3D support, so volume rendering support fails. There is also no PBuffer support. No texture compression support either so standard VPB generated models just result in white models. The vertex throughput is also very poor, even small models like cow.osg just return max frame rates of 200fps while I normally get many thousand of fps on ATI and NVidia. Big town models also really slow when lots of objects/geometry are in the scene. I kinda suspect that the drivers aren't well optimized for the vertex load. However, we are just talking about onboard graphics from Intel here... I wasn't expecting a high performance graphics monster, what it is a pretty capable machine for light graphics loads, and is really efficient on power. My big tripple SLI motherboard + Quad core + high end graphics card would suck over 200W even at iddle, now it just sips away with 88W on iddle. Considering the machine is still pretty powerful machine with first gen (65nm) Quad core processer this is pretty impressive, it's finally lower enough for me not to worry about my kids surfing the web on a high end machine and burning a hole in the household budget or monster carbon footprint. The other side to note is that finally I have machines with all three major graphics vendors represented so I can do testing of the OSG across a better spread of desktop hardware, For the last decade I have pretty well exlusively been developing using NVidia graphics, simple because they've always has the best OpenGL drivers. My testing this week has shown that NVidia still do have the best OpenGL drivers, but that both ATI and Intel are now doing a pretty decent job - neither are perfect but they are now finally getting to play in the same ballpark as NVidia. Robert.
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