Quad FX with 4 7950GT's, Xinerama issues
I got a 8 screen monster here, running core 6 64 bit with 4 7950GT's (and a lotta extra fans, temps are a-ok). I'm using it to drive a flight simulator with 7 ****pit displays, and one extra display on the side for us lowly code monkeys to use. Out-the-window imagery is driven by a separate linux cluster.
Each display is its own X display, and not bound with a virtual framebuffer. Needless to say, they all scream. They can all run quite fast simultaneously, which is perfect for my current application.
Just for kicks and giggles we decided to change them all to the same resolution (1024x768 each for testing) and enable xinerama with GLX acceleration. The system came up fine, and speed was good across 3 displays (of the 8). However, once I started expanding the 3-D window across the 4th display (second output of the second card) my fantastic frame rates came to a crawl (i.e. less that 1 fps).
I'm still under the 4096x4096 opengl viewport size, why would the nvidia performance come to a crawl at this point? Ideally I would like to have the 8 displays arranged in a grid with a single virtual framebuffer.
I did not use any twinview configurations BTW. Any tips, or is this a current limitation that I can't overcome at the moment?