Revised 2026-09-20

Uses

What I measure things with, and what I measure them on. Two of these matter to the numbers in the notes and the rest are here because people ask. There are no brand names on purpose - a specification is reproducible, a brand is an advertisement.

The two machines

Both appear in every note, described the same way each time so the numbers stay comparable.

• The desk machine - a 2019 four-core desktop part rated at 65 W, 16 GB of memory, one SATA solid-state disk, one gigabit link, the display powered off at the monitor so it is not in the measurement. This is the quiet one, and the one most of the idle-state numbers come from.
• The shelf server - a 2022 eight-core server board, 64 GB, two NVMe disks, two gigabit links, no graphics card, on an actual shelf. It is the louder of the two and the one I use when a note needs more than four cores or a second disk to say anything.

Both run the same long-term 6.6 kernel, deliberately. One of the open questions on the now page is whether the headline metric survives moving the shelf server off that series, with the desk machine held back as a control.

The instrument

• An inline mains meter at the wall, 0.1 W resolution, logged once a second to a file. It cost rather less than it should have, which is the single biggest limit on what these notes can honestly claim - anything under about 0.3 W is inside its own error and I say so when it comes up.
• A paper notebook, one page per measurement, the date and the exact machine state written at the top before the first number. It is the only thing on this list I would be genuinely upset to lose, because it is the part that makes a figure from two years ago trustworthy.

Software

• A modal terminal editor I have used since about 2011 and will not be changing. Everything on this site was written in it.
• A plain shell and a short stack of my own scripts for sampling counters, which are on their third rewrite - the first two died of being too general. The surviving one refuses to print a counter as a total,.
• A terminal mail reader, because the one address on this site reaches a human who reads it twice a day and nothing more clever is warranted.
• The kernel's own documentation tree, read like a book, which earns its mention on the reading page.

The desk itself

• A mechanical keyboard from 2014 that has outlived three computers and will outlive a fourth.
• A window layout I spent a weekend configuring in 2020 and have barely touched since, which is the correct amount of time to spend on one.
• No second monitor, no chat client for work, and no counter on this site telling me you were here - a choice I occasionally regret, as the contact page admits.

If you want the exact model of any of this, I will tell you by mail, but I keep it off the page so the numbers are read as numbers and not as a recommendation to go and buy the same part.