I've got an old MacBook Pro with a Core2Duo CPU that regularly has a load up in the 3s or 4s.
thumper:~ joliver.sa$ sysctl -n hw.ncpu 2 thumper:~ joliver.sa$ uptime 9:24 up 4 days, 16:31, 3 users, load averages: 3.50 4.09 3.83 Processes: 295 total, 2 running, 14 stuck, 279 sleeping, 1225 threads 09:24:43 Load Avg: 3.59, 4.06, 3.83 CPU usage: 4.83% user, 6.28% sys, 88.88% idle SharedLibs: 17M resident, 20M data, 0B linkedit. MemRegions: 48719 total, 3030M resident, 159M private, 655M shared. PhysMem: 7200M used (1446M wired), 991M unused. VM: 698G vsize, 1071M framework vsize, 0(0) swapins, 0(0) swapouts. Networks: packets: 38837251/53G in, 7236342/639M out. Disks: 1045731/15G read, 1170955/228G written.
This clearly isn't a CPU issue. It doesn't appear to be a memory issue. Disk IO doesn't seem to be an issue. Some of the "stuck" processes were things I could kill off, but the load has only gotten worse in the last few minutes. How else can I find out what's lining up waiting for attention?