slow pbuffer speed

[Paulius]

I encountered some strange speed issues when using a pbuffer for rendering to a texture, for example I downloaded this demo from delphi3D http://www.delphi3d.net/download/arbrendertex.zipand got such results: copying a texture from a framebuffer 400FPS, copying a texture from a pbuffer 150FPS, using pbuffer as a texture 65FPS. I got similar results on a couple of PC?¢_~s. As I see it results should have been the other way around, any thoughts?

[Alimonster]

WGL_ARB_render_texture was by far the quickest for me (a few hundred FPS, I forget the exact figure), then copying from the framebuffer (about half that speed). The pbuffers ran at 6 (six!) frames per second -- maybe these results depend on drivers (I used Cat 3.9, ATI 9500).

[Paulius]

I only did tests on nVidia cards with 4*.** detonator drivers, very strange stuff, guess I?¢_~ll stick with the ?¢_oofficially slowest?¢__ framebufer copying method, which seam?¢_Ts to at least work acceptably on all cards.