I posted this on the TS forums for someone... since I went to the effort of taking some comparison screenies I thought I would post it here again as well just for the hell of it.
Using the "-maxnodesize" parameter in hlbsp can significantly lower r_speeds on some maps. I am not sure precisely how it works, but it seems to effect how your map is broken up and thus how it is VISed.
The default setting, ie what it is if you specify nothing, is 1024. I find that for maps with huge, open area 4096 sometimes works best. For maps with smaller areas, where you want less 'bleedover' between areas, -512 seems to work best. It is best to experiment with different values, though, to see which works best. This setting will effect different parts of the map differently, so see which is best overall, and/or lowers speeds where help is most needed.
[thanks to Banana for teaching me this one]
I wrote that a while back... generally I find 512 to be the best setting, seems to make the VISing more accurate or something. But your milage may vary, sometimes the default 1024 is the best anyway. Someone told me changing the maxnodesize didn't work so well with hint brushes, but it didn't cause me any issues.
I took some screenies to show the effects of this parameter, they are in this directory:
http://www.cryotank.net/remote/maxnodesize/
These were taken from 2 different bsps, each from the exact same .map, but compiled with a different maxnodesize settings. You will notice a 100-200 wpoly difference between the pics in each set. Note that in one case the '512' pic actually has -higher- rspeeds. This is in a low-traffic area, though, and since 512 seemed to lower speeds overall in the map I chose to use that custom setting for the final compile.
Like I said... it's something worth trying on your map, since sometimes it lets you get a good rspeed reduction with almost no effort or changes to the mapfile itself.
(I would have included the screenies in the post, but they are 1024x768 and the rspeeds aren't legible if I reduce them since I forgot to add the new font wad last time I installed AHL.)
