- Quantum computer performance is evaluated using three metrics: programmable qubits, qubit operations, and maximum circuits per second.
- Programmable qubits measure scale as the number of qubits users can directly control in algorithms.
- Qubit operations measure quality by indicating how many complex two-qubit operations a system can reliably execute.
- Maximum circuits per second measures speed and circuit throughput, key for price-performance and cost efficiency.
- These metrics apply across all quantum hardware modalities, including superconducting, trapped-ion, and quantum-dot systems.
- IBM defines programmable qubits as those that can be prepared, manipulated, and measured, distinct from supporting physical qubits.
- Future fault-tolerant quantum computing will use T-gate count instead of two-qubit operations as a quality proxy.
- Circuit throughput is a simple measure for comparing computational work across different quantum platforms.