This is an odd bug. In fact, I'm not even sure if it is a bug.
I have a scene with about 200 polygons being drawn using FreeGlut and default shaders. Each polygon can optionally have face normals superimposed, using something simple like
glVertex3f( (VA.x)*A+a, (VA.y)*A+b, (VA.z)*A+c);
glVertex3f( (VB.x)*A+a, (VB.y)*A+b, (VB.z)*A+c);
on each polygon face, which point outward along the normal. Prior to the 275.09.07 driver, showing the normals slowed my frame rate by about 30%.
Since a fresh update of X, nvidia, and a kernel26 reinstall, when I run the code without
showing the normals, the mouse and keyboard input become extremely
choppy, the scene update becomes choppy, but my overall framerate does not drop.
If I run the code with
showing normals, the choppiness nearly disappears. The code has a much higher framerate compared with no normals. There is a slight degradation in framerate compared with prior nvidia driver, but it is at least useable.
Candidly, It 'feels' like the buffer has been pushed onto hard disk when I run without showing the normals.
I have no noticeable effects running my desktop manager or glxgears. As I mentioned, I just reinstalled X*, nvidia, and my kernel because of issues loading the the 'glx' module (the solution to this problem was to remove an old version of libglx.so.)
I'm at a loss here. I don't even know where to ask, really. I could probably make a video showing what I am talking about, but I doubt it would help diagnose what the issue is.