Why vx is fast: five decisions, not a trick
A fully cached run of 3,270 tasks finishes in about half a second with no daemon. That number is the sum of five structural decisions, each of which is also a correctness win.
performance
4 posts with the tag “performance”
No daemon, on purpose
A daemon answers 'what changed' quickly by keeping a second copy of the truth. vx keeps no copy. Every run pays its own discovery and still wins the warm benchmarks, because the discovery was made cheap instead of being hidden.
Bitsets, popcount, and a scheduler tick that re-scans nothing
On a 3,270-task graph, computing scheduling priority with set unions took 8.5 seconds. Packed bitsets with popcount take single-digit milliseconds. This post is the scheduler: what it computes, how it picks the next task, and the two-tier trick that keeps restores off the critical path.
Benchmarks you can re-run
Two benchmarks: a synthetic 1,090-package workspace where all three runners see the same graph, and solidjs/solid, a real Turbo repository with vx on top of its own turbo.json. Every number is a command away, and the cold rows are read honestly.