TwinView and Xinerama Performance

[DrJ]

I have installed an FX1000 to drive my dual CRTs. The first X configuration I tried was a simple modification of my existing xorg.conf that uses Xinerama. I thought that TwinView would give better performance (it has to manage only a single buffer) so I reconfigured for TwinView.

Using a simple glxgears test for screening, I found that Xinerama gave better performance: about 7000 fps vs. 2200 fps. That seems odd: is that usual? Is the test valid?

DrJ