[cperciva]

Pretty much. If you want to get fancy you can make assumptions about the distribution of request arrival times and use the mean queue length of 6 to estimate the fraction of the time when the queue length drops to zero; you probably come out somewhere around 10% CPU idle time, so each request is taking 15 ms to process rather than 16.6 ms.

But cpu-time-per-request is definitely the number you want to pay attention to. If you cut that by a factor of 2, you won't decrease the load average from 6 to 3; you'll decrease it from 6 to less than 1.