IBM ibmqx2

IBM · Apache-2.0 last capture 2021-03-15

ibmqx2 is a 5-qubit IBM quantum computer, with records from 2019 to 2021.

On its latest calibration (15 March 2021), a typical two-qubit operation failed about 1 in 47, better than 14% of the 65 other devices in this record.

The newest record is from 15 March 2021, 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
0.984142
fails about 1 in 63

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

Better than 5% of 65 other devices with this measurement
Measured 2021-03-15
Median 2Q error
IBM · Apache-2.0
0.0214228
fails about 1 in 47

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

Better than 14% of 65 other devices with this measurement
Measured 2021-03-15
Median T1 (µs)
IBM · Apache-2.0
48.234

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

Better than 1% of 67 other devices with this measurement
Measured 2021-03-15
Median T2 (µs)
IBM · Apache-2.0
24.545

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

Better than 3% of 67 other devices with this measurement
Measured 2021-03-15
Median readout error
IBM · Apache-2.0
0.0633
fails about 1 in 16

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

Better than 9% of 67 other devices with this measurement
Measured 2021-03-15
Qubits
IBM · Apache-2.0
5

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

Measured 2021-03-15

History

Each point is one dated measurement (8 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
2021-03-15T05:02:20
Raw source (latest snapshot)
https://github.com/Qiskit/qiskit-ibm-runtime/blob/2a396172c25aa2971e99b434b430177745878a53/qiskit_ibm_runtime/fake_provider/backends/yorktown/props_yorktown.json

Cite this page

@misc{provenova_ibm_ibmqx2,
  title        = {IBM ibmqx2 — calibration & benchmark history},
  howpublished = {\url{https://provenova.net/hardware/ibm/ibmqx2}},
  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.