Architecture Comparison Capstone

There is no best quantum architecture for everything. A fair comparison first fixes one job. Then it scores each architecture on four things: how well its links fit the job, what the gates compile into, timing, and dated error evidence. Example arithmetic shows a trapped-ion profile winning on success per shot (0.970 vs 0.904 on a ten-gate circuit). Meanwhile a superconducting profile runs thousands of times more shots per second. The ranking depends on the circuit and the evidence, never on one headline number.

Why is there no universal winner?

"Which QPU is best?" is an unfinished question. It is like asking "which vehicle is best?" without saying whether you are moving a parcel or a piano. A bike wins for the parcel. A truck wins for the piano. The finished question is: best for this circuit, under this deadline, judged by this standard of evidence.

A fair comparison works through a fixed checklist. You built every item in earlier lessons:

Execution model: gate-based or annealing? If they differ, stop comparing (see lesson 7).
Qubit definition: physical qubits, or error-corrected logical qubits built from many physical ones (see lesson 2)?
Topology: which pairs can interact directly, and what does routing cost (lesson 8)?
Native gates: what does your circuit compile into, and what is its real pulse count (lesson 9)?
Timing: how long gates take, and how often the machine can repeat a shot.
Error evidence: fidelities (chances each gate works) with method, scope, aggregation, date, and uncertainty (lessons 10–11).
Disclosure limits: what is simply not published, recorded as such.

The rest of this capstone runs one small job through that checklist with real arithmetic.