I'm developing a small demo for behaviour trees and I'm having some issues when running it on AMD hardware.
I've tested my code with four configurations:
MacBook Pro (NVidia GT650M) - fine
Desktop with CentOS 6.5 (Nvidia Quadro FX) - fine
Desktop with Windows 7 64 bit (AMD HD7950 with Catalyst 14.4) - slow
Desktop with Fedora 19 (AMD HD7950 with catalyst 14.4) - slow
3 and 4 are actually the same machine. The code is not highly optimized but it's not doing anything too complex
either: I have a grid (which I render using GL_POINTS), a line that represents the path found by A* and a moving
agent. The grid has about 10k elements, if I remove that the demo runs better, but still not perfectly.
I guess it's a driver issue, as on 3 and 4 it seems it's running with software rendering; I profiled the code on Windows
with CodeXL and a frame take ~400ms and seems to be using mostly the CPU rather than the GPU.
As final information, I'm using GLEW and GLFW for cross-platform development. The full code is available here:
Thanks in advance for the help and let me know if you need any further information!
Original answer posted here: http://www.gamedev.net/topic/659012-issue-with-opengl-demo-using-catalyst-drivers-linux-and-windows/#entry5168395
It seems that for this particular card GL_POINTS are emulated in software and that's causing the demo to slow down. I will change the grid to triangles
to make sure it runs smoothly on all cards.