So after editing the limiting file, I was able to get realtime output
   at sr=44100/ksmp=1 down to -b2 -B4 by adding the --sched flag. ( Do
not do this unless you are using a short score, it will lock up your 
machine on failure until the score is finished. ) I have Ingo Molnar's 
patch applied to 2.6.12, but have not even tweaked out the system as 
much as possible. Apparently the card will not accept lower settings, 
will find out if this is truely the case.

Theoretically that gives us a csound latency of 0.1 to 0.2 milliseconds. 
I am not sure what my soundcard additional hardware latency is, but I 
think it is between 0.7 to 1.5 ms, so this bodes very well for realtime 
fx processing. ( Though I am sure the figures will not be that good for
round trip. on my card.)

Iain