Reasoning benchmark performance scales logarithmically with test-time compute, while multi-agent parallelization is the mechanism used to buy more effective test-time compute than a single serial agent can produce — implying the engineering lever is horizontal agent fan-out with an explicit parallelization penalty, not more thinking tokens alone.
If returns on thinking tokens are logarithmic but parallel agents add compute concurrently, the dominant cost/performance decision shifts from model size to inference topology: how many agents, how they coordinate, and what budget each is given.
Any system where a serial reasoning loop hits diminishing returns can be restructured as parallel independent reasoners plus a reconciliation step, but the reconciliation overhead (parallelization penalty) sets the effective ceiling.
Performance on reasoning benchmarks scales logarithmically with test-time compute.
Multi-agent scaling allows test-time compute to run in parallel.
Inference optimization and reasoning budgets will replace raw parameter scaling as primary competitive advantages.