&gt; Load average measures how long is the queue of processes waiting for the CPU<p>I don&#x27;t think that&#x27;s quite right.<p>Load averages measure the size of queue of processes runnable and waiting for CPU or disk.<p>If you ever have a webserver&#x2F;cache that has disks that have become the bottleneck, you can often get to a high load (lots of runnable processes, blocked on disk) but low CPU util (everything is blocked on disk, CPU relatively idle).<p>In my experience high UNIX load on busy systems is far more caused by disk IO utilisation rather than CPU utilisation.<p>E.g. if you run &quot;du -s &#x2F; &amp;&quot; 4 times, you can watch your UNIX load go to 4 (after 1 minute), but you will have idle CPU time.  This will be more obvious if you have slow magnetic disks rather than a fast SSD.