The largest quantum volume

[ Front page ] [ The edge ] [ Finished ] [ About ] [ Links ]


8,388,608 quantum volume

Held by Quantinuum H2. Set 2025-05-12, and has stood for 505 days. Written down here 2026-09-11.

Counting qubits is a poor way to compare quantum computers, because a machine with many unreliable qubits can do less than one with a few good ones. Quantum volume was proposed to fix that. It asks for the largest square circuit a machine can run and still be right more often than not, so error rates, connectivity and qubit count all collapse into a single figure, and it doubles, which is why it is always quoted as a power of two. Every figure is a manufacturer's claim about its own machine and no part of the field runs a leaderboard for them, so the only list that puts them side by side is one volunteers keep. That makes this the weakest-sourced number on this page, which is why the claim behind a reading is read at the manufacturer as well before it is written down. This frontier continues an earlier one of the same name, now on the finished page, which was closed for having taken the newest figure in that list instead of the largest.

That description was written when this frontier was opened, on 2026-09-11, and is never rewritten. Where it and the number above it disagree, the number is the reading and the description is history.


What counts
The highest quantum volume any manufacturer has claimed for a working machine: the largest figure in the cross-manufacturer list, which is not the same thing as the most recent one. A reading is taken only when the manufacturer's own announcement of that figure has been read as well. Quantum volume only - not qubit counts, which are not comparable between machines.
What moves it
A manufacturer claims a higher figure and the list records it. Quantum volume doubles, so the next step is always twice the standing record.

Where to check it: https://en.wikipedia.org/wiki/List_of_quantum_processors


Last checked: 2026-09-29


Previous: The largest prime number ever found   Next: The smallest a gigabyte of Wikipedia has ever been made

[ Front page ] [ The edge ] [ Finished ] [ About ] [ Links ]