I also see extremely poor performance with glCopyPixels when copying from GL_BACK to GL_FRONT, especially when I apply a zoom of anything other than 1. This is on my Quadro 580 XGL. Sizes are of the magnitude of 256x256 or so. I don't if Quadro 980 XGL will make it any faster.
I see a really really slow response, 2-3 seconds if I use a transformation matrix. Something is surely wrong.
These are definitely too slow. Our application works way better on IRIX with V6/V12 graphics.