Equalizer just got something new for all you ray-tracing and volume rendering people out there: Pixel compounds. The load is always almost equally distributed, thus allowing to scale the fill-rate nearly linearly.
The frustum for the source channels gets distorted so that the channel only renders 1/nth of the pixels in one dimension. Afterwards the frustum is moved slightly to select the ‘starting’ point of the channel.
OpenGL functionality which is influenced by the raster position will not work correctly with pixel compounds, or needs at least special attention. Among them are: lines, points, glRasterPos, glPolygonStipple.
On the right you’ll see an image of it in action. The backgrounds are colored differently for illustration purposes. Click on the image for a high-res version.