> 3x might be a bit too much today, but it's definitely slower than C.
If anything the gap is increasing not shrinking. JVM is terrible at memory access patterns due to the design of the language, and designing for memory is increasingly critical for maximum performance on modern systems. All the clever JIT'ing in the world can't save you from the constant pointer chasing, poor cache locality, and poor prefetching.
The gap won't shrink until Java has value types. Which is on the roadmap, yes, but still doesn't exist just yet.
The problem with those benchmarks is if you look at the Java code you'll see it's highly non-idiomatic. Almost no classes or allocations. They almost all exclusively use primitives and raw arrays. Even then it still doesn't match the performance on average of the C (or similar) versions, but if you add the real-world structure you'd find in any substantial project that performance drops off.
Ah, thanks for the link; I wasn't sure what it meant in the context of Java, since it's possible to get value semantics using a class.
Sorry about the confusion. I meant for the quotes around "copy-only" to indicate that it wasn't really a standard term, but I marked "value types" the same way, so that didn't really work. By "copy-only" I meant something you couldn't have more than one reference to: every name (variable) to which you assign the data would have its own independent copy.
> By "copy-only" I meant something you couldn't have more than one reference to: every name (variable) to which you assign the data would have its own independent copy.
That's not really a requirement of value types, no. C# has value types (structs) and you can have references to them as well (ref & out params).
In general though yes it would be typically copied around, same as an 'int' is. Particularly if Java doesn't add something equivalent to ref/out params.
Wouldn't you say there's a difference between "effective" and "getting away with it"? If non-technical users see that their daily computing lives are made more complicated (because of lowered performance) by having n Electron apps running at the same time, they may not understand the reasons, but they will certainly choose a different solution that has the features they need, where available.
Agreed, and ironically the most widely used Java platform (Android), despite its VM optimizations, is the one which would benefit the most from running only native code.
I mean, those 1GB RAM 7 years old slow as molasses phones getting dust into drawers or being littered into landfills would scream if they didn't have to run everything behind a VM.
Make no mistake — Android isn't memory hungry because of Java alone. Android 4 used to comfortably fit in 1Gb of RAM, but Android 10 no longer can run on such devices. Both old and new versions use JVM, but newer Android has a lot of "helpful" system services, such as "Usage Statistics" service [1] and "Autofill Servide" [2].
Google's spyware is becoming more invasive and thus more memory-hungry.
Really depends on the domain. There's some things that are a lot easier to make scale up in a language with a great concurrent gc, because that makes writing some lock free data structures quite fundamentally easier (no complicated memory reclamation logic, trivial to avoid ABA problems).
GC makes it easier to write, but not necessarily better. Modern state-of-the-art Java GCs operate a global heap, so you often pay for what you do not use. In languages like Rust or C++ your can build small locally GCed heaps, where you can limit GC overhead to just a few particular structures that need GC, not everything. Therefore other structures like caches don't affect GC pause times.
And the "hardness" of writing lockless structures is strongly offset by libraries, so unless you're doing something very exotic, it is rarely a real problem.
Here are some benchmarks; I'll leave to the experts out there to confirm or dismiss them.
https://benchmarksgame-team.pages.debian.net/benchmarksgame/...