About this Document¶
This document is for users of a D-Wave™ quantum computer system who want to understand how their use of the system is timed, which bears on how their use of the system will be accounted.
The document is written with increasing levels of detail in later sections. End users wishing only to understand how their use of the D-Wave system is being accounted can read only through Chapter 2. Application and tool developers and those assessing system performance will often want the detail of later sections.
This document describes the computation process, focusing on system timing, on D-Wave quantum computers. 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, and describes the timing-related fields in the Solver API (SAPI), both for user control and measurement.
This document uses the following terms:
- 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.