How we check the numbers

Every number here is either read from a document we archived or is our own estimate, and each page says which.

The archive

When we take a figure from a vendor page or specification sheet, we fetch it, store the exact bytes, record a SHA-256 hash and the time we retrieved it. The sources page lists every archived document, and each figure shows the fragment it was read from, so you can check our reading against the original. A retrieval date is not a promise that the figure is still current. When a page changes, the old figure is superseded rather than overwritten.

What the labels mean

Vendor documented means the vendor states this figure in the document we archived, and the page quotes the sentence. Vendor recommended means the vendor calls it a recommendation rather than a requirement. Our estimate means we produced the number, and the page shows the working: either derived from a documented statement, such as turning a per-process memory figure into a figure for four processes, or reasoned from scratch where the project publishes nothing usable.

We never label an estimate as documented. A number that can be neither sourced nor honestly estimated is left out, and the calculators treat it as unknown.

Two things we deliberately do not publish. No vendor in our set states what one of these machines draws at the wall, and processor base power is not wall power, so every power figure is our estimate and a plug meter will beat all of them. Used hardware prices vary by country, week and seller, so the calculators ask for the price you can actually get.

The sizing model

Memory is the sum of the applications you chose plus a shared operating system allowance, times one plus a headroom fraction. Storage works the same way, with your own files added separately. CPU is the largest single demand plus half of the rest, because peaks only partly coincide. Every input is on the page and all of them are editable.

Verdicts are capacity ratios, not performance guarantees. Comfortable means at least 1.2 times the modelled need everywhere. Not recommended means one dimension is short. Unknown means an input is missing, which is never treated as a pass. The model knows nothing about codecs, camera counts, USB radios or disk speed.

The cost model

Owning costs the purchase price once plus electricity and upkeep. Renting costs the monthly price times the months plus any setup fee. Electricity uses the Eurostat half-yearly household average, taxes included, and you can pick a country or type your own tariff. Prices are held constant, with no discounting, resale value or financing, and your time is not priced. Where a provider publishes a renewal price we use that one for multi-year totals. We hold no exchange rate, so plans priced outside the euro are left for you to convert.