[Milhouse]

On a 512M board we can probably afford more memory to go to the queues and fifos. No way of specifying that externally, but if you are building your own, you could play with these sizes.
Look for small_mem in xbmc/cores/omxplayer, and you can see the sizes of buffers used for 256M and 512M boards. Might be interesting to try increasing them.

With your latest GPU/time fix I'm not seeing any playback performance issues right now - kind of a shame the fifo queues can't be tuned in advancedsettings but I know there is resistance to that kind of thing (perhaps understandable).

I took a quick look at omxplayer and it seems to be allocating the following memory to the queues:

Code:

audio: 3MB (256MB) and 6MB (512MB)
video: 10MB (256MB) and 40MB (512MB)

I've got no problems right now with these values (512MB board) but I guess if I were connecting over WiFi or had a really lousy network it might be beneficial to use larger values.