Out of Browser courses

Where the energy actually goes

Joules, not vibes. Measure what your own work costs before joining an argument about data centres.

What this course is

The energy argument about computing is conducted almost entirely in ratios, with no magnitudes and no boundaries. This course gives you magnitudes, starting with your own.

You will put a meter on your own machine, work out what an hour of your actual work costs in watt hours and grams of CO₂, and then find the point where the second-order effects swamp the first.

What you'll leave with

  • A measured figure for your own inference workload, in watt hours per task.
  • A carbon figure using your grid's real intensity at the hour you ran it, not an annual average.
  • A rebound estimate — what happens to total consumption when each unit gets cheaper.

What this is not

It is not a case for or against anything. It is the arithmetic that lets you evaluate a claim, including the ones you would like to be true.

Module 0 — Measure your own

Free. A plug meter costs less than a takeaway and settles more arguments.

  1. The unit is joules — Ratios without magnitudes mislead in both directions, and almost every public figure is a ratio. (20 min)
  2. Put a meter on it — Your own machine, your own workload, your own grid, at the hour you actually ran it. (25 min)
  3. The rebound — Efficiency and total consumption are separate variables, and confusing them is how good news becomes wrong news. (20 min)

Related writing

  • What actually fits in 8GB of VRAM — The arithmetic behind model size, quantisation and context length — so you can work out what runs on the GPU you already own before downloading 40GB to find out.
  • What your machine actually costs to run — A £15 plug meter settles the energy question for your own hardware in an afternoon: idle draw, load draw, watt-hours per task, and what that comes to per year.
  • Local or hosted: where the crossover actually is — The break-even between a GPU you own and an API you rent is a division, not an argument. Here is the calculation, with the terms people leave out.