Classically, UNIX systems have calculated the load average by counting the number of processes that are either running on the CPU or runnable (ready & waiting for a CPU to run them). Linux does this, but it also counts the number of processes in uninterruptable sleep. Uninterruptable sleep usually means a process is blocking on I/O (waiting for disk, etc.).

As such, you can't really use a Linux host's load average to determine the CPU utilization of the host. If the load is high you might have an I/O problem instead of a CPU bottleneck. Then you need tools like vmstat, top, iostat, etc. to tell you what is actually going on.

This doesn't mean load average is useless, though. From a monitoring standpoint it's something that can tell you at a glance that something is wrong. Just remember that higher load averages aren't necessarily bad. If your 16 CPU machine has a load of 16 that might just mean it's being fully utilized.