Definition
Plain language
How long something actually takes in real-world seconds, as opposed to how much computation it does.
As stated in the literature
Elapsed real time for a computation, distinct from FLOPs or token counts; used as the budget axis in challenges like Autoresearch and as a cost metric for sandbox checkpointing, agent search, and RL training throughput.
Also called: wall-clock, wall clock
Why it matters: It captures how long users and researchers actually wait, which is the cost that matters in practice regardless of raw computation counts.
For example, a task might take ten real-world minutes even if the computer was doing heavy calculation for only part of that stretch.
Heard on the show
“The whole thing ran on a single laptop — RTX A1000, six gigabytes of GPU memory, about 10 hours wall-clock.”Episode 025 — The Missing Gradient Term That Predicts Sycophancy in RLHF