Reserve system time¶

Overview¶

Under standard operating conditions, IBM Quantum systems accept jobs according to the dynamic priority assigned by the fair-share queuing system.

While this system attempts to balance workloads for the benefit of all users, there are often use cases where you may require limited-time access at a higher priority level. IBM Quantum provides two means by which users associated with a selected instance can gain elevated access to specific systems over a specified period of time: Priority mode and Dedicated mode. Depending on your hub configuration, if you are a hub admin or group admin, you can reserve time in advance on a particular system with the Systems Reservations tool.

Priority mode¶

When submitting many self-contained jobs or hosting events (i.e., courses, tutorials, or hackathons), you may need to bypass the queue altogether and send jobs from a given instance straight to the front of the queue for one or more systems. This is called priority mode access in IBM Quantum.

In priority mode, all jobs from the specified instance submitted during the scheduled priority mode time go to the front of the queue for the specified system. Jobs process in the order in which the instance receives them (first-in first-out). Jobs submitted before a priority mode reservation are considered part of the normal queue, and do not move to the front. If the instance with priority access does not submit jobs, then the normal fair-share queue pipeline opens until another priority job is received.

In priority mode, the system is never idle as long as jobs are submitted. At the end of a priority mode reservation, any priority jobs that have not be executed will return to the standard fair-share queue.

Dedicated mode¶

If you need sole access to a specific quantum system for a given instance, select dedicated mode when making a reservation.

Unlike priority mode, the standard fair-share queue is always blocked when the device is in dedicated mode.

This allows users to implement algorithms where input circuits are conditioned on previous results, such as iterative and near-time compute methods, without having to wait for other users’ results to process. If the dedicated instance has multiple users, then a single user’s jobs may be queued behind those of other users in the instance, as the execution is first-in first-out. Other functionality is identical to that of priority mode.

Selecting the correct reservation mode¶

To determine the appropriate mode for your reservation, consider the table below, which offers guidance based on some common use cases.

Work with reservations¶

For instructions to work with reservations, see Manage your system reservations.