With my patch open i get these values (average): cpu1 60% cpu2 60% cpu3 11% cpu4 2% Then, when I open a pd~ patch: cpu1 80% cpu2 80% cpu3 40% cpu4 3%
the average cpu load won't tell you a lot, since the cpu speed is usually not constant, but may be modulated (adding some latency hotspots). in general, i'd recommend to disable frequency scaling, turbo mode (for nehalem cpus) and smt, since it may confuse numbers and can increase the thread wakeup latency significantly, if you want to use a machine for low-latency real-time audio applications.
so, still plenty of overhead on the 4th core, but it doesn't seem to be used.
from my understanding, you should split your path into 4 pieces of equal load, using 3 pd~ objects, if you want to optimize it for a quad-core cpu.
tim