Hi,
On my rpi with pd 0.46-1 I cannot use -rt: /home/pi/pd-0.46-1/bin# ./pd -rt -alsa -nogui priority 96 scheduling failed; running at normal priority priority 98 scheduling failed.
With pd 0.46.0 all is good: /home/pi/pd-0.46-0/bin# ./pd -rt -alsa -nogui priority 96 scheduling enabled. priority 98 scheduling enabled.
Cheers~