Skip to main content
← Lab

tokenasym

confirmedPython · llama.cppInference & servingJuly 6, 2026

the question

How much more does an output token cost than an input token?

what came out

An order of magnitude more: 12.8x for the 1.5B, 22.0x for the 0.5B (input 0.48/0.17ms vs output 6.18/3.69ms), and the gap grows with prompt length. Prefill is cheap; generation is where the bill is. All three pre-registered predictions held.

method & receipts

  • Result: confirmed
  • Pre-registered the prediction was written down and committed before the run.
  • Reproducible one script re-runs the whole thing from scratch.
  • Independently reviewed an adversarial review pass, kept in the repo.
  • Machine-readable claims every reported number, in a checkable file.
  • Tested — a correctness/benchmark suite ships alongside the code.

→ read the code and re-run it

github.com/v-code01/tokenasym