IBM ibmq_essex

IBM · Apache-2.0 last capture 2020-08-10

ibmq_essex is a 5-qubit IBM quantum computer.

On its latest calibration (10 August 2020), a typical two-qubit operation failed about 1 in 44, better than 11% of the 65 other devices in this record.

The newest record is from 10 August 2020, so the machine may since have been upgraded or retired.

Every figure below is the device's latest measurement of that metric, with its own date and source. See how the whole field is progressing →

Best 2Q fidelity
IBM · Apache-2.0
0.988897
fails about 1 in 90

Success rate of the chip's single best pair of qubits. The best pair flatters the chip; the typical one matters more.

Better than 14% of 65 other devices with this measurement
Measured 2020-08-10
Median 2Q error
IBM · Apache-2.0
0.0226514
fails about 1 in 44

How often a typical two-qubit operation on this chip fails, from the vendor's own calibration.

Better than 11% of 65 other devices with this measurement
Measured 2020-08-10
Median T1 (µs)
IBM · Apache-2.0
65.607

How long a typical qubit holds its state before it decays, in microseconds. Longer leaves more time to compute.

Better than 15% of 67 other devices with this measurement
Measured 2020-08-10
Median T2 (µs)
IBM · Apache-2.0
105.13

How long a typical qubit keeps its delicate quantum phase, in microseconds.

Better than 55% of 67 other devices with this measurement
Measured 2020-08-10
Median readout error
IBM · Apache-2.0
0.0363
fails about 1 in 28

How often reading a typical qubit's value at the end gives the wrong answer.

Better than 22% of 67 other devices with this measurement
Measured 2020-08-10
Qubits
IBM · Apache-2.0
5

Physical qubits on the device. More only helps if they are good enough to use together.

Measured 2020-08-10

History

Each point is one dated measurement (5 snapshots in total).

Best 2Q fidelity
Median 2Q error
Median T1 (µs)
Median T2 (µs)
Median readout error
Qubits

Provenance

Source
IBM · Apache-2.0
Licence
Apache-2.0 · Qiskit fake backend calibration snapshot
Raw redistributable
yes
Captured
2020-08-10T06:54:13
Raw source (latest snapshot)
https://github.com/Qiskit/qiskit-ibm-runtime/blob/2a396172c25aa2971e99b434b430177745878a53/qiskit_ibm_runtime/fake_provider/backends/essex/props_essex.json

Cite this page

@misc{provenova_ibm_ibmq_essex,
  title        = {IBM ibmq_essex — calibration & benchmark history},
  howpublished = {\url{https://provenova.net/hardware/ibm/ibmq_essex}},
  publisher    = {Provenova},
  note         = {accessed 2026-10-19}
}

Compare with

vs ibm ibm_aachen 5 shared metrics vs ibm ibm_algiers 5 shared metrics vs ibm ibm_auckland 5 shared metrics vs ibm ibm_berlin 5 shared metrics vs ibm ibm_boston 5 shared metrics vs ibm ibm_brisbane 5 shared metrics vs ibm ibm_brussels 5 shared metrics vs ibm ibm_cairo 5 shared metrics

Data: real IBM device calibration published in Qiskit's fake backends (Apache-2.0). Rankings on the live leaderboard.