Explain what isn’t working. Are you using shaders? Rendering to fixed-point fb causes clamping. Maybe you are rendering to floating-point framebuffers/pbuffers?
Thank you for your answer but i’ve resolved i think, the problem was that rgbe image was not power of two.
If i use float texture that are not power of two (even empty texture) frame rate goes down to 1 fps (i think opengl switch to software mode), if i use texture that are power of two frame rate is normal (200 fps). I’m using an ati card, i don’t know if it is normal this behavior…
ATI cards don’t support the ARB_texture_npot extension fully, so for OpenGL 2.0 compatibility they have to fall back to software when using NPOT textures under centain conditions.
I don’t know the exact restrictions of NPOT textures on ATI hardware, but I think at least mipmapping is not allowed…