Hello everybody,
First post. Let me just say that I am very impressed with what I have seen from Ogre so far. However, I have a question regarding OpenGL performance. I just installed the Terrain demo (as laid out in the absolute newbie's guide) and I get about 40fps when I run it using OpenGL and about 400fps when I use Direct3D. I guess I was expecting performance to be about even, not a 10x difference. Was I wrong in expecting this? Perhaps somebody could explain why this is happening. BTW, my system is an AMD 64 3000+ (2.2 GHz) with 1GB 400MHz RAM and a Chaintech nVidia geForce 5700LE vid card with 256MB VRAM.
Thanks.
Very, very strange! And sorry I have to ask, but are you sure you didn't compare a debug and a release build? Otherwise it has to be a serious driver issue, I guess.
I'd say definitely an old driver issue. A couple of the older nVidia drivers had some serious performance issues with the GL extensions we use which were fixed in later versions. I have a 5900 and GL performance is very slightly under Dx9, but that's because of a known issue with the nVidia VBO implementation. It's not enough to get worried about though (5% ish iirc)
DWORD: Yeah, I tested both Direct3D and OpenGL on the same build, so it is not a difference between builds.
Thanks a lot everybody, now I know that this is somewhat abnormal behavior. I will check to see if I can find some updated drivers and see if that fixes the problem.