Benchmark: Quantum volume

Benchmarks / System level (whole processor)

A single number for the largest random circuit of equal width and depth that a computer runs successfully.

Level: System level (whole processor)
Maintained by: Defined by Cross et al. (2019); results are mostly self-reported by vendors.
European: No
Reference: https://arxiv.org/abs/1811.12926

How it is measured

Random circuits of equal width and depth and of increasing size are compiled and run, and their outputs are checked against ideal classical simulation. The result is reported as a power of two, for example 2^16 for a trapped-ion processor in Moses et al. (2023).

Limitations and criticisms

Needs classical simulation of the circuits, so it cannot certify very large machines.
Square random circuits do not represent structured applications (Proctor et al. 2022).

Used in European procurements

Used in: EuroHPC procurement Euro-Q-Exa (Required in the benchmark suite (scored under the award criteria))
Used in: EuroHPC procurement LUMI-Q (now VLQ) (Required in the benchmark suite (scored under the award criteria))
Used in: EuroHPC procurement EuroQCS-Italy (now SOL) (Required in the benchmark suite (scored under the award criteria))
Used in: EuroHPC procurement MeluXina-Q (Mandatory requirement with a minimum)

As the tender documents state; how a benchmark is weighted against others is described in each procurement.

Sources

A. W. Cross et al. (2019). Validating quantum computers using randomized model circuits. Phys. Rev. A 100, 032328 (2019); arXiv:1811.12926. Read: abstract page, retrieved 2026-10-23.
S. A. Moses et al. (2023). A Race Track Trapped-Ion Quantum Processor. Phys. Rev. X 13, 041052 (2023); arXiv:2305.03828. Read: abstract page, retrieved 2026-10-23.