About this Document

Intended Audience

This document is for users of D-Wave™ solvers who want to understand how their use of the system is timed, which bears on accounting.

Scope

This document describes the computation process of D-Wave quantum computers, focusing on system timing. It explains the overall time that is allocated to a quantum machine instruction (QMI), describes how use of the quantum processing unit (QPU) is timed within that period, gives context for how timing can vary.

For QPU and Leap‘s hybrid solvers it describes the timing-related fields in the Solver API (SAPI).

Glossary

This document uses the following terms:

  • Hybrid solvers: Quantum-classical hybrid solvers implement state-of-the-art classical algorithms together with intelligent allocation of the QPU to parts of the problem where it benefits most.
  • Quantum processing unit (QPU): Quantum computational element within a D-Wave system.
  • Quantum machine instruction (QMI): Set of information that is sent to the QPU, including the Ising model or QUBO parameters and annealing-cycle parameters.
  • Annealing cycle: Physical process of starting with the QMI (prepared for the D-Wave system) and yielding a single sample to the QMI. Typically executed multiple times in a single QMI.
  • Sample, result, read, or solution: Terms for the result yielded by an annealing cycle; ‘sample’ is preferred to connote the nondeterministic behavior of the QPU.