Catalog — Metric definitions
What hardware metrics actually mean
Every metric page defines the figure, explains how it is measured, and — the part most spec sheets omit — states when two values of it are not comparable. That caveat is the difference between reading a spec sheet and being misled by one.
Definitions5 metrics
dimensionlessTwo-qubit gate fidelityTwo-qubit gate fidelity measures how close a processor's entangling gate comes to its ideal operation — the single most consequential figure on a spec sheet, because two-µs / ms / sCoherence times (T1 and T2)T1 is how long a qubit holds its energy state; T2 is how long it holds phase information. Together they bound how much circuit you can run before the quantum state decaysdimensionlessReadout fidelityReadout fidelity is the probability that measuring a qubit reports the state it was actually in. Every shot pays this cost once per measured qubit, so it caps the accuraclayersCircuit depthCircuit depth is the number of sequential layers of operations after parallelizing everything that can run simultaneously — the length of the critical path, and a direct qubitsQubit countQubit count is the register size — and by itself it ranks nothing. Usable capacity depends on connectivity, fidelity, and your circuit's shape; counts across different ex