[torrance]

Whilst the Julia version currently beats Mojo, I fully expect both to approach basically the same performance with enough tinkering, and for that performance to be on par with C or Fortran.

A more interesting question is which version is more elegant, ‘obvious’ and maintainable. (Deeply familiar with both, but money is on Julia).

[sundarurfriend]

> A more interesting question is which version is more elegant, ‘obvious’ and maintainable. (Deeply familiar with both, but money is on Julia).

Yes, more than raw speed, what impresses me is that the version of code in [1] is already a few times faster than the Mojo code - because that's pretty basic Julia code that anyone with a little Julia experience could write, and maintain easily.

The later versions with LoopVectorization require more specialized knowledge , and get into the "how can we tune this particular benchmark" territory for me (I don't know how to evaluate the Mojo code in this regard as yet, how 'obvious' it would be to an everyday Mojo developer). So [1] is a more impressive demonstration of how an average developer can write very performant code in Julia.

[1] https://discourse.julialang.org/t/julia-mojo-mandelbrot-benc...

[sundarurfriend]

User lmiq articulates the sentiment well in a later comment in the OP thread:

> what I find more interesting here is that the reasoning and code type applies to any composite type of a similar structure, thus we can use that to optimize other code completely unrelated to calculations with complex numbers.

It matters less whether super-optimized code can be written in Julia for this particular case (though there's some value in that too), the more important and telling part to me is that the language has features and tools that can easily be adopted to a general class of problems like this.

[nologic01]

An even more interesting question is: which version will actually entice millions of independed and variably motivated actors from all walks of life to commit and invest to a particular ecosystem. Technnical and usability aspects play only a minor role in technology adoption. In particular the best technology doesnt always win.

My humble two pennies is that Julia is missing the influencer factor: being endorsed by widely known entities that will attract the attention of both corporate eyes and the hordes of developers constantly looking for the next big thing.

Your money might be on Julia but $100mln was just placed on the Mojo/Modular bet...

[patrick451]

I've tried julia a handful of times. IMO, the thing slowing adoption is that the usecases where julia feels like the most powerful, optimal choice are too limited. For example

- Slow startup times (e.g., time-to-first-plot) kill it's a appeal for scripting. For a long time, one got told that the "correct" way to use julia was in a notebook. Outside of that, nobody wanted to hear your complaints.

- Garbage collection kills it's appeal for realtime applications.

- The potential for new code paths to trigger JIT compilation presents similar issues for domains that care about latency. Yes, I know there is supposedly static compilation for julia, but as you can read in other comments here, that's still a half baked, brittle feature.

The second two points mean I still have the same two language problem I had with c++ and python. I'm still going to write my robotics algorithms in c++, so julia just becomes a glue language; but there's nothing that makes it more compelling that python for that use. This is especially true when you consider the sub-par tooling. For example, the lsp is written julia itself, so it suffers the same usability problems as TTFP : you won't start getting autocompletions for several minutes after opening a file. It is also insanely memory hungry to the extent that it's basically unusable on a laptop with 8gb of ram (on the other hand, I have no problem with clangd). Similarly, auto-formatting a 40 line file takes 5 seconds. The debugging and stacktrace story is similarly frustrating.

When you take all of this together, julia just doesn't seem worth it outside of very specific uses, e.g., long running large scale simulations where startup time is amortized away and aggregate throughput is more important than P99 latency.

[amj7e]

Some of what you have written seems pre 1.0 release and some pre 1.9. I have never seen anybody in the community say the correct way to use Julia is in a notebook. As far as I have seen, some people use a simple editor and have the REPL open, and most just use it in vscode.

You can do real-time applications just fine in Julia, just preallocate anything you need and avoid allocations in the hot loop, I am doing real-time stuff in Julia. There are some annoyances with the GC but nothing to stop you from doing real-time. There are robotics packages in Julia and they are old, there is a talk about it and compares it with c++(spoiler, developing in julia was both faster and easier and the results were faster).

I have been using two Julia sessions on an 8gb laptop constantly while developing, no problem. LSP loads fine and fast in vscode no problem there either.

The debugger in vscode is slow and most don't use it. There is a package for that. The big binaries are a problem and the focus is shifting there to solve that. Stacktrace will become much better in 1.10 but still needs better hints(there are plans for 1.11). In general, we need better onboarding documentation for newcomers to make their experience as smooth as possible.

[patrick451]

The recommended solution to slow startup times has always been keep a repl open. That's basically the same workflow as a notebook in my mind. Like I said this means there is a large class of tasks julia a doesn't make sense for because paying the startup cost is too expensive compared to python or go.

I just timed vscode with the lsp. From the point I open a 40 line file of the lorenz attractor example, it takes 45 seconds until navigation within that same file works, and the lsp hogs 1 GB of memory. That's 5x the memory of clangd and 20x worse performance; hardly what I would consider a snappy experience.

I have no doubt that julia can be shoe-horned into realtime applications. But when I read threads like this [1], it's pretty clear that doing so amounts to a hack (e.g., people recommending that you somehow call all your functions to get them jited before the main loop actually starts). Even the mitigations you propose, i.e., pre-allocating everything, don't exploit any guarantees made by the language, so you're basically in cross-your-fingers and pray territory. I would never feel comfortable advocating for this in a commercial setting.

[1] https://discourse.julialang.org/t/julia-for-real-time-worrie...

[amj7e]

I don't know man, I just tested vscode and it's almost instant, loads every function from multiple files in less than 5 seconds. I'm on a 13-inch intel Mac and Julia 1.11 master (1.9 and 1.10 should be the same).

Having a REPL open is not the same thing as a notebook, if you feel like that, cool I guess.

That thread is old and Julia can cache compiled code now from 1.9 and onward. However, it can not distribute the cached code(yet).

Writing the fastest possible real-time application in c/c++ has the same principles as in Julia. It's not as shoe-horned as you might believe.

When developing Julia, the developers chose some design decisions that affected the workflow of using the language. If it doesn't fit your needs that's cool, don't use it. If you are frustrated and like to try the language come to discourse, people are friendly.

[patrick451]

>I don't know man, I just tested vscode and it's almost instant, loads every function from multiple files in less than 5 seconds. I'm on a 13-inch intel Mac and Julia 1.11 master (1.9 and 1.10 should be the same).

I know, I'm always "holding it wrong". And that's the problem with julia.

> Having a REPL open is not the same thing as a notebook, if you feel like that, cool I guess.

Both workflows amortize the JIT times away by keeping an in-memory cache compiled code. This makes a lot of smaller scripting tasks untenable in julia. So people chose python instead. That means julia needs a massive advantage elsewhere if they are going to incorporate both languages into their project.

> When developing Julia, the developers chose some design decisions that affected the workflow of using the language. If it doesn't fit your needs that's cool, don't use it. If you are frustrated and like to try the language come to discourse, people are friendly.

This thread was about why julia hasn't seen wider adoption. It's my contention that the original design decisions are a one of the root causes of that.

[Certhas]

I think the person you are replying to was using notebook as shorthand for interactively. You don't write scripts that you call, you have to have a repl open to interactively feed code to.

Autocompletion in Julia is also just terrible and the tooling really is lacking compared to better funded languages. No harm in admitting that (when Julia had no working debugger some people were seriously arguing that you don't need one: Just think harder about your code! Let's please bury that attitude...)

[amj7e]

This certainly has not been my experience with Julia people. Sure there are opinionated people in every community, but most of pain points are acknowledged and known.

[DNF2]

I can confirm that there were multiple (heated) arguments on Discourse, where some posters completely dismissed the need for debuggers in general. I remember it quite well.

It was very strange, but I don't think it says anything about the community, except that people have different opinions and preferences, like in any community.

[sundarurfriend]

>> For a long time, one got told that the "correct" way to use julia was in a notebook. Outside of that, nobody wanted to hear your complaints.

> I have never seen anybody in the community say the correct way to use Julia is in a notebook.

patrick's comment is fully in the past tense for this part, and that was indeed a pretty common thing for a long while in the past. Especially pre-1.0, before Revise became mature and popular, an oft-recommended workflow was to use a notebook instead of an editor. Or it would come in the form of a reply to criticism about the slow startup or compilation latency - "the scientists who this language is made for use notebooks anyway, so it doesn't matter" was a common response, indirectly implying that that was the intended way to use the language.

[DNF2]

You must mean REPL, not notebook. I've been following the community since before the move to Discourse, and "use the REPL" surely outnumbers "use a notebook" by orders of magnitude.

[sundarurfriend]

Here on HN (in threads about Julia) the focus was generally on notebooks as I remember it. That's the context I assumed, but if it's about Julia fora in general I agree, the REPL had/has been talked about much more often than notebooks.

[suavesito]

About the show startup times, they have been worked massively in the latest version of Julia. Mainly in version 1.9, which is the first version of Julia that saves native compiled code. You can RAAF more about that in the released blog [1].

On garbage collection and real-time applications, there is this [2] talk where ASML (the manufacturer of photolithography machines for TSMC) uses Julia for it. Basically it preallocates all memory needed before hand and turns off the garbage collector.

On the same more about real-time, if your call stack is all type stable [3], the you can be sure that after the first call (and subsequent compilation), the JAOT compiler won't be triggered.

About static compilation, there are two different approaches * PackageCompiler.jl [4], which is rally stable and used in production today. It has he downside of generating huge executables, but you can do work to trim them. There is still work to do on the size of them. * StaticCompiler.jl [5], which is still in the experimental phase. But it is far from being completely brittle. It does puts several restrictions on the chide you can write and compile with it, basically turning Julia in a static type language. But it had been successfully used to compile linkable libraries and executables.

Some of the concerns you have about usability in your third paragraph have been worked on with the 1.9 and 1.10 (coming) releases. The LSP usage is better thanks to native code caching, maybe you can try it again (of you have time). The debugging experience I honestly think is top notch if you're using Debugger.jl+Revise.jl [6] [7], still I know there are some caveats in it. About stack traces, there is also a more of work done to make them better and more readable, you can read the with done in these PR's [8] [9] [10] [11, for state of Julia talk].

Still, I can understand that Julia might not be able (yet) to cover all the usecases or workflows of different people.

[1]: https://julialang.org/blog/2023/04/julia-1.9-highlights/#cac... [2]: https://www.youtube.com/watch?v=EafTuyy7apY [3]: https://docs.julialang.org/en/v1/manual/performance-tips/#Wr... [4]: https://julialang.github.io/PackageCompiler.jl [5]: https://github.com/tshort/StaticCompiler.jl [6]: https://github.com/JuliaDebug/Debugger.jl [7]: https://timholy.github.io/Revise.jl/stable/ [8]: https://github.com/JuliaLang/julia/pull/49117 [9]: https://github.com/JuliaLang/julia/pull/49959 [10]: https://github.com/JuliaLang/julia/pull/45069 [11]: https://www.youtube.com/watch?v=2D8oRtDJEeg&t=2487

[bwanab]

You may very well be right, but for my money Alan Edelman (MIT) is influencer enough.

[sa-code]

IMO the reason Julia gets to be this fast is because of LLVM, and the guy who created LLVM is also the creator of Mojo so there is something to be said about that

[sundarurfriend]

My understanding is that Julia gets to be this fast because the language design was optimized for performance from the beginning, by clever use of its type hierarchy and multiple dispatch for compilation into very specific and efficient machine code (plus a thousand other little optimizations like constant propagation, auto-vectorization, etc.)

LLVM helps with its own optimizations, but more and more of those optimizations are being moved to the Julia side nowadays (since the language has more semantic understanding of the code and can do better optimizations). I believe the main thing LLVM helps with is portability across many platforms, without having to write individual backends for each one.

[sa-code]

That's fair, I'm not really a compiler person but what you said makes sense

[__rito__]

One language is literally some months old, and another is 11 years old. Not a fair comparison at this point, and for some years to come.

The gap will definitely narrow.

[Max-Limelihood]

Not necessarily. Julia will always be 11 years older than Mojo, no matter how old both of them get, and that advantage won't shrink. Not to mention, Mojo is a superset of a 40-year old language with billions of dollars of development poured into it, plus an extra hundred million poured directly into Mojo itself. If we go by resources spent on each, Mojo has had gotten about 5x more investment than Julia.

[eigenspace]

yeah pretty much any strongly performance oriented modern language should be able to be massaged into emitting whatever instructions should give close to optimal performance here.

It's always fun though when one language does better naïvely in a benchmark to delve in and see how to match or surpass them, and see if it was worth the trouble.

Microbenchmark performance for languages in this class definitely shouldn't be seen as a strongly deciding factor though.

[jakobnissen]

I disagree, actually. I have found microbenchmarks to be very informative to understand why a language is fast in some cases and slow in others.

It's not only the actual benchmark numbers though. Its understanding the code that reaches those numbers: Can Julia do explicit SIMD? How awkward is that in one language or the other? Are there idiosyncratic bottlenecks? Bad design decisions that needs to be worked around in one language but not the other? And so on.

[eigenspace]

Agreed. I was just saying the number often isn't so informative since pretty much any of these languages can achieve those speeds.

How the language gets to that number is of course very enlightening