I posted this article because I found it thought-provoking, and I hadn't heard of the Breguet Number and Carson’s Speed. But it does seem to me rather half-bake

I posted this article because I found it thought-provoking, and I hadn't heard of the Breguet Number and Carson’s Speed. But it does seem to me rather half-baked (or even only one third ;-). I was hoping that someone else would set the mess straight, including sorting out the vague definitions, but no such lazyweb luck this time ... First thing that looks wrong to me is that server power estimate at one-third. I occasionally see CPU reviews with white-boxes benchmarking at something like 120W for idle power and 200W for full-throttle work, for CPUs rated at 90W or so. Perhaps racked servers have less overhead, but I doubt they do any significant work at 1/3 of full power. But I'd be happy to be contradicted by someone with real info. P.S. Coincidentally, in the LWN piece I also linked yesterday (http://news.ycombinator.com/item?id=2564007 http://news.ycombinator.com/item?id=2564007 ), commenters samth and incase provided links to info about an IBM Research tool (Performance Analysis of Idle Programs, by Erik Altman et al.). Web page: https://researcher.ibm.com/researcher/view_project.php?id=1332 https://researcher.ibm.com/researcher/view_project.php?id=13... . PDF paper: https://researcher.ibm.com/researcher/files/us-sjfink/res0000076-altman.pdf https://researcher.ibm.com/researcher/files/us-sjfink/res000...