Comment by smarnach
Twice as fast at executing JavaScript? There's absolutely zero chance this is true. A JavaScript engine that's twice as fast as V8 in general doesn't exist. There may be 5 or 10 percent difference, but nothing really meaningful.
Twice as fast at executing JavaScript? There's absolutely zero chance this is true. A JavaScript engine that's twice as fast as V8 in general doesn't exist. There may be 5 or 10 percent difference, but nothing really meaningful.
johnfn@mac ~ % time deno eval 'console.log("hello world")'
hello world
deno eval 'console.log("hello world")' 0.04s user 0.02s system 87% cpu 0.074 total
johnfn@mac ~ % time bun -e 'console.log("hello world")'
hello world
bun -e 'console.log("hello world")' 0.01s user 0.00s system 84% cpu 0.013 total
Keep in mind that it's not just a matter of comparing the JS engine. The runtime that is built around the engine can have a far greater impact on performance than the choice of v8 vs. JSC vs. anything else. In many microbenchmarks, Bun routinely outperforms Node.js and Deno in most tasks by a wide margin.
The claim I responded to is that Bun is "at least twice as fast" as Deno. This sounds a lot more general than Bun being twice as fast in cherry-picked microbenchmarks. I wasn't able to find any benchmark that found meaningful differences between the two runtimes for real-world workloads. (Example: https://hackernoon.com/myth-vs-reality-real-world-runtime-pe...)
You might want to revise what you consider to be "absolutely zero chance". Bun has an insanely fast startup time, so it definitely can be true for small workloads. A classic example of this was on Bun's website for a while[1] - it was "Running 266 React SSR tests faster than Jest can print its version number".
[1]: https://x.com/jarredsumner/status/1542824445810642946