I've been using Kombustor 1.1.2 over the last few days to get a stable OC on my new HIS 5770. It's been going well, but then I discovered a drastic difference between D3D and OpenGL results. I was hoping people here could weight in with their thoughts on the results. In D3D11 @ 950/1375 I can run Kombustor for 45+ min w/ 8xaa. It may go longer, but I just stopped it at 45 min. However, when I run it in OpenGL 3 @ 950/1375 w/ no aa, it can only run 2 min. I continued to drop down the memory overclock, stopping @1300. @ 950/1300 it can't make it more than a few minutes. My Question: Is there something abnormal about this, or are the OpenGL benchmarks more strenuous? Thanks
yep you're right DX11 render path is a bit light. Here are some quick results with a GTX 480 (settings: unlocked power draw, 1024x768 windowed mode, no AA, no postfx): DX11 - GPU usage: 93% and power consumption: 368W DX10 - GPU usage: 99% and power consumption: 390W DX9 - GPU usage: 99% and power consumption: 406W GL3 - GPU usage: 99% and power consumption: 405W GL2 - GPU usage: 99% and power consumption: 404W (power consumption at the wall socket). I will check that.
I've also been wondering if the ATI Drivers are just not very robust for OpenGL based apps. I used default clocks, and still bombed out fairly quickly testing OpenGL, but can run for an hour plus at defaults in D3D.
ATI's drivers have a very long history of issues with OpenGL. Just ask any OpenGL developer and they'll tell you of all the ATI specific workarounds they have to perform because of ATI's lack of full standards compliance.