Hamlet has a tip he got from Trinity Dejavu over on Reddit. See: Simple Trick to Speed Up Second Life Rendering.
The ‘trick’ is to turn off avatar rendering when you first arrive in a crowded place. (Ctrl-Alt-Shift-4) One press turns off avatar rendering and a second press will turn it back on. B turning it off your viewer can concentrate on rendering the ‘area’. Later when you render avatars they ‘seem’ to render faster because the viewer just has to render them as all else is already rendered.
This doesn’t make it any faster or actually reduce render time. Actual time to a final render is probably longer. But, psychologically we break the wait time into two parts with each being less than the single pass render but added together… more. Basically it is just easier on our patience.
But, I haven’t put a stop watch on it yet…