Rigetti cepheus-1-108q

Metriq · CC-BY-4.0 last capture 2026-08-05

cepheus-1-108q is a 107-qubit Rigetti quantum computer.

In Metriq's independent test (24 July 2026), a layer of operations across a 10-qubit chain failed about 1 in 490.

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 →

EPLG (error/layer)
Metriq · CC-BY-4.0
0.00204942
fails about 1 in 490

Metriq's independent test of a 10-qubit chain: how often a layer of two-qubit operations fails, measured end to end.

Better than 60% of 5 other devices with this measurement
Measured 2026-07-24
Bell-state effective qubits
Metriq · CC-BY-4.0
5

The largest connected group of qubits that all pass a Bell-state entanglement test.

Better than 40% of 5 other devices with this measurement
Measured 2026-07-24
QFT accuracy
Metriq · CC-BY-4.0
0.001

How well the machine runs a small quantum Fourier transform benchmark: 1 is perfect, 0 is no better than noise.

Better than 60% of 10 other devices with this measurement
Measured 2026-08-05
QAOA approx. ratio
Metriq · CC-BY-4.0
0

How much better than random guessing a simple optimisation algorithm does on this machine: 1 is perfect, 0 is no better than chance.

Better than 0% of 10 other devices with this measurement
Measured 2026-07-24
Qubits
Metriq · CC-BY-4.0
107

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

Measured 2026-08-05

History

Each point is one dated measurement (3 snapshots in total).

QAOA approx. ratio
Qubits

Provenance

Source
Metriq · CC-BY-4.0
Licence
CC-BY-4.0 · metriq.info
Raw redistributable
yes
Captured
2026-08-05T07:07:09
Raw source (latest snapshot)
https://github.com/unitaryfoundation/metriq-data/blob/main/LICENSE

Cite this page

@misc{provenova_rigetti_cepheus_1_108q,
  title        = {Rigetti cepheus-1-108q — calibration & benchmark history},
  howpublished = {\url{https://provenova.net/hardware/rigetti/cepheus-1-108q}},
  publisher    = {Provenova},
  note         = {accessed 2026-10-19}
}

Compare with

vs ibm ibm_boston 3 shared metrics vs ibm ibm_fez 2 shared metrics vs ibm ibm_kingston 2 shared metrics vs ibm ibm_marrakesh 2 shared metrics vs ibm ibm_pittsburgh 3 shared metrics vs ibm ibm_torino 3 shared metrics vs iqm iqm_emerald 2 shared metrics vs iqm iqm_garnet 3 shared metrics

Data: Metriq community benchmarks (metriq.info, CC-BY-4.0). Rankings on the live leaderboard.