Pyston v2: A JIT‑Enhanced Python Interpreter 20% Faster Than CPython

In 2014, the original Pyston project was launched by Dropbox with the goal of creating a high‑performance Python implementation that could compete with system‑level languages like C++.

Pyston uses a JIT compiler: Python code is translated to LLVM IR, optimized by LLVM, and then JIT‑compiled to native machine code.

After six years of development, the team released Pyston v2 on October 28, 2020.

Pyston v2: 20% Faster Than Python

According to the developers, macro‑benchmarks show Pyston v2 is about 20% faster than Python 3.8, reduces server costs, shortens user‑perceived latency, and boosts developer productivity.

The interpreter is also easy to deploy; a simple package installation can replace the standard Python binary and improve performance with minimal effort.

Performance

Pyston v2 delivers noticeable speed gains across many workloads, not only web‑server benchmarks but also a variety of common benchmarks.

The team created a new public Python macro‑benchmark suite to measure performance of several popular Python projects.

In micro‑benchmarks such as chaos.py and nbody.py , Pyston v2 runs roughly twice as fast as standard Python.

On target benchmarks (DjangoCMS + FlaskBlogging), Pyston v2 achieved an average latency improvement of 1.22× and a p99 latency improvement of 1.18×, while memory overhead per process increased by only a few megabytes.

Technical Methods

Low‑overhead JIT using DynASM

Quickening

General CPython optimizations

Process‑building enhancements

Compatibility

Because Pyston is a fork of CPython, it claims the strongest compatibility among Python implementations, supporting all CPython features and the C API. In practice, new implementations may encounter temporary compatibility issues; details are available on the project wiki.

Usability

Pyston v2.0 is available as pre‑built packages for Ubuntu 18.04 and 20.04 (x86_64). Installation involves replacing the python3 binary with pyston3 and reinstalling dependencies via pip‑pyston3 , a change that can be made with only a few lines in existing build scripts.

The team plans to open‑source the code in the future, though the compiler component remains closed due to high development costs; Pyston v1.0 source code is already open.

Original article: https://blog.pyston.org/2020/10/28/pyston-v2-20-faster-python/