Hi. I'm using PyPy3 in the context of a game engine and I'm getting these spikes when timing it, such as: Engine: 3.0 ms Engine: 3.9 ms Engine: 3.0 ms Engine: 7.9 ms Engine: 25.1 ms Engine: 2.2 ms Engine: 2.2 ms Engine: 3.1 ms Engine: 3.0 ms Engine: 4.2 ms When I run the engine on CPython 3, the timings are more consistent: Engine: 1.7 ms Engine: 1.8 ms Engine: 1.2 ms Engine: 1.8 ms Engine: 1.7 ms Engine: 1.3 ms Engine: 1.6 ms Engine: 1.8 ms Engine: 1.9 ms Engine: 1.5 ms I've gotten spikes when timing much simpler things. I don't believe my code is doing anything exceptional to cause the spikes. My educated guess is it's due to the GC or more likely the JIT. When I run the engine with JIT off like so, "pypy3 --jit off main.py", the spikes disappear (albeit not as fast with it on). I've also been playing around with the minimark settings but no luck so far; possibly tweaking the JIT settings might help. Any suggestions are welcomed :). Specifications: pypy3 --version: Python 3.2.5 (b2091e973da69152b3f928bfaabd5d2347e6df46, Nov 18 2014, 20:15:54) [PyPy 2.4.0 with GCC 4.9.2] uname -a: Linux archlinux 3.17.6-1-ARCH #1 SMP PREEMPT Sun Dec 7 23:43:32 UTC 2014 x86_64 GNU/Linux Sincerely, Kevin Ednalino