When rendering 1080i60 source files to MainConcept AVC interlaced, rendering takes about twice as long as it does to render the same material to 30 fps progressive (with everything else in the render templates being equal). Am I doing something wrong, or is this just the nature of the beast with this encoder? I would prefer to render interlaced to retain temporal / resolution information, but for this workstation's application, rendering speed is critical.
BTW I'm using GPU acceleration with a GTX570 in Studio Platinum 13. GPU acceleration seems to be working, at least for the progressive renders, as it significantly reduces the rendering time relative to CPU-only rendering.