Sampling with Hybrid Solvers#

The quantum-classical hybrid solvers in the Leap service are intended to solve arbitrary application problems formulated as a nonlinear model or quadratic model[1].

These solvers, which implement state-of-the-art classical algorithms together with intelligent allocation of the quantum computer to parts of the problem where it benefits most, are designed to accommodate even very large problems. Hybrid solvers enable you to benefit from D‑Wave’s deep investment in researching, developing, optimizing, and maintaining hybrid algorithms.

Using the Stride Solver

Using the Stride™ hybrid solver.

Using the Stride Solver
Other Hybrid Solvers

Other hybrid samplers.

Other Hybrid Solvers

D-Wave also provides a Python framework for building a variety of flexible hybrid workflows. The dwave-hybrid Development Framework section describes this framework.

Solver Timing#

The table below lists the timing information returned from quantum-classical hybrid solvers in the Leap service.

Table 2 Timing Information from Hybrid Solvers#

Field

Meaning

run_time

Time, in microseconds, the hybrid solver spent working on the problem.

charge_time

Time, in microseconds, charged to the account.[2]

qpu_access_time

QPU time, in microseconds, used by the hybrid solver.[3]

You can access this information in the returned Future object from the hybrid nonlinear solver (or via the dimod SampleSet class for other hybrid solvers), as in the example below.

>>> from dwave.optimization.generators import bin_packing
>>> from dwave.system import LeapHybridNLSampler
...
>>> model = bin_packing([3, 5, 1, 3], 7)
>>> with LeapHybridNLSampler() as sampler:
...     results = sampler.sample(
...         model,
...         label='SDK Examples - Knapsack')
>>> results.result().info["timing"]
{'qpu_access_time': 319883, 'charge_time': 5000000, 'run_time': 5026351}

Solver Usage Charges#

D‑Wave charges you for time that solvers run your problems, with rates depending on QPU usage. You can see the rate at which your account’s quota is consumed for a particular solver in the solver’s property_quota_rate property; for example, quota_conversion_rate for the nonlinear solver.

You can see the time you are charged for in the responses returned for your submitted problems. The relevant field in the response is 'charge_time'. The example in the Solver Timing section shows 'charge_time': 5000000' in the returned response, meaning five seconds are being charged.

Instantiating the needed compute resources for your problem can introduce a delay before the problem is processed. This delay tends to be small compared to the overall solution time for large problems. The charge_time does not include this delay.