how to acelerate texture in post-prossecing?

i want do post-processing, all steps are to render to texture and to copy the final texture in the screen, this is really slow, down at 20 fps.

the last step is to copy the final texture in the screen, the code is:


	glDisable(GL_BLEND);	
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D,texf2); 
	glColor4f(1,1,1,1);	 
	glBegin(GL_QUADS);
	glTexCoord2f(0.0f, 0.0f); glVertex2f(0.0f, 0.0f);
	glTexCoord2f(1.0f, 0.0f); glVertex2f(1, 0.0f);
	glTexCoord2f(1.0f, 1.0f); glVertex2f(1,1);
	glTexCoord2f(0.0f, 1.0f); glVertex2f(0.0f,1);
	glEnd(); 



that’s all, and this consumes up to 20 fps

although not draw anything, remains slow

while the window is bigger, slower turns
Is there any solution?

Are you using an FBO? A pixel buffer? glCopyTexSubImage2D? What hardware have you?