Comment by moralestapia 5 days ago
Very interesting post, thanks for putting it together.
Rust is indeed quite fast, I thought NodeJS was much better tbh., although it's not bad. I'd be interested to learn what's holding it back because I've seen many implementations where V8 can get C++-like performance (I mean it's C++ after all). Perhaps there's a lot of overhead in creating/destroying temporary objects.
One reason is that I did not spend much time optimizing the Node and Rust versions, I just translated the Python logic as directly and quickly as I could. At least I did not ask an LLM to do it for me, which I hope counts. ;-)
Edit: fixed a couple of typos.
V8 gets C++-like performance when it is getting code that JITs very well. This is typically highly-numeric code, even sometimes tuned specifically for the JIT. This tends to cause a great deal of confusion when people see the benchmarks for that highly numeric code and then don't understand why their more conventional code doesn't get those speeds. It's because those speeds only apply to code you're probably not writing.
If you are writing that sort of code, then it does apply; the speed for that code is real. It's just that the performance is much more specific than people think it is. In general V8 tends to come in around the 10x-slower-than-C for general code, which means that in general it's a very fast scripting language, but in the landscape of programming languages as a whole that's middling single-thread performance and a generally bad multiprocessing story.
For the bubble sort implementation, it's due to the use of the destructuring assignment in the benchmark code. When swapping to a regular swap using a temporary variable, the benchmark runs more than 4 times faster on my machine. Still not at Rust level of performance, but a bit closer to it.
> V8 can get C++-like performance (I mean it's C++ after all)
I don’t think that follows. Python is written in C, but that doesn’t mean it can get C-like performance. The sticking point is in how much work the runtime has to do for each chunk of code it has to execute.
(Edit: sorry, that’s in reply to another child content. I’m on my phone in a commute and tapped the wrong reply button.)