this is because (unlike a traditional BSP), my approach doesn't "choose" the plane, it calculates it.
basically, all you really need is an averaged center-point, and a vector describing how the "mass" is distributed relative to the point.
Ah, I see, that sort of calculation should be relatively cheap to what I was imagining. Thanks for explaining.
even then, it isn't usually as much of an issue at present, as memory bandwidth has increased considerably over the past several years (relative to CPU speed increases), making the limit harder to run into (currently typically only really happens during bulk memory-copies and similar AFAICT, rather than in general-purpose code).
it was much worse of a problem 10 years ago though.
This is good to know. A lot of what I know about game programming is, unfortunately, dated to roughly 10 years ago. It doesn't help that I was reading a bunch of articles from Intel recently to catch up, who may be blowing the bandwidth issue out of proportion (I don't know, just a guess).