Thinking about CPU

Charles Hooper has written a number of impressive blog posts in a fairly short space of time (the man is a blogging machine!) but I really wanted to draw attention to one in particular.

Fault Quotes 6 - CPU Utilization

Why? Well I seem to be spending more and more of my time talking about these issues to people and even pointing out that

"It is important to keep in mind that at any one instant, a CPU (or core or CPU instruction thread) is either 100% busy or 0% busy – at any one instant a CPU cannot be 75% busy."

is a good start (let's not start getting into multi-threaded cores or weird architectures until people get the basics right). I immediately passed the link around several good people at my current customer site and Twittered about it (which won't be happening again ) but figured I should mention it here too.

If I have one slight criticism, it's that the post is *long* and you'll need to put some time aside to read it, particularly if you click through all the links. I've had an ongoing discussion with Martin Widlake about optimum post-length but I hope I'm wrong in this case and people give it a chance.

Without offering any absolute answers, it's thought-provoking stuff and if it does make you think about queuing, throughput, CPU utilisation, averages or whatever, can I recommend Cary Millsap and Jeff Holt's Optimizing Oracle Performance (again)? It covers these subjects in more depth and with an Oracle slant.

I'll rest happy when 'CPU utilisation is still below 100%' has stopped being the golden metric!

(... and, no, this is not the long-awaited technical posts starting, but Charles is saving me the bother of all that stuff!