Python 3.15 free-threaded: 3.8x faster, but 85% of counts lost
Python 3.15's free-threaded build ran pure-Python work 3.8x faster on 8 threads, and the standard build ran it 1.0x. The same build also lost 85% of the increments to an unlocked shared counter, where
Thu Oct 22 2026 · 11 min read · 0 views