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Re:JavaScript engines zoo – Compare every JavaScript engine by DarkFuture on Sunday January 04, 2026 @07:50AM (#46487453)
Disappointing for Firefox for such lower performance.

I just ran the JetStream2 benchmark and got:

- Firefox: 159 score

- Chromium: 235 score

That's on latest Fedora Linux and Ryzen 3600 CPU.

Re:JavaScript engines zoo – Compare every JavaScript engine by p_ing on Sunday January 04, 2026 @09:06AM (#46488077)
M2 Air w/ 24GB RAM macOS 26.2:

- Firefox: 253.584

- Safari: 377.470

- Chrome: 408.332

- Edge: 412.005

Re:JavaScript engines zoo – Compare every JavaScript engine by quantum_bit on Monday January 05, 2026 @04:16PM (#46505083)
My results similar with M4 Pro (12 cores, 16 cores GPU), 24 GB RAM macOS 26.2 (the same benchmarks, I guess, https://browserbench.org/JetStream2.0/):

Firefox: 298.136

Safari: 425.762

Just the last test in this test suite:

> 3d-cube-SP > 3D cube rotation benchmark by Simon Speich. The original can be found on Simon's web page. Tests arrays and floating-point math in relatively short-running code.

gives the following results:

Firefox: 305.197

200 First 338.983 Worst 419.309 Average

Safari: 818.449

238.095 First 176.471 Worst 1957.237 Average

which shows that in this particular test, Safari is 2.5 times faster.

Re:JavaScript engines zoo – Compare every JavaScript engine by tralarpa on Sunday January 04, 2026 @10:05AM (#46488625)
Similar results here.

I'm curious to know what the problem of Firefox is. For example, the 3d-raytrace-SP benchmark is nearly three times faster on Edge than on Firefox on my i7 laptop. The code of that benchmark is very simple and mostly consists of basic math operations and array accesses. Maybe the canvas operations are particularly slow on Firefox? This seems to be an example that developers should take a look at.

Re:JavaScript engines zoo – Compare every JavaScript engine by 360MustangScope on Sunday January 04, 2026 @02:37PM (#46491403)
The developers are busy ramming AI into it by management. This is probably never going to get looked into.
Re:JavaScript engines zoo – Compare every JavaScript engine by nicoburns on Sunday January 04, 2026 @03:17PM (#46491752)
> Maybe the canvas operations are particularly slow on Firefox

That seems likely. WebRender (Firefox's GPU accellerated rendering backend) doesn't do vector rasterization. So Firefox rasterizes vectors using the CPU-only version of Skia and then uploads them to the GPU as textures. Apparently the upload process is often the bottleneck.

In contrast, Chrome uses (GPU-accelerated) Skia for everything. And Skia can render vector graphics directly into GPU memory (at least part of the rasterization pipeline is GPU accelerated). I would expect this to be quite a bit faster under load.

It's a known problem, but I hear that almost all of the Gecko graphics team's capacity beyond general maintenance is going towards implementing WebGPU.

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SpiderMonkey is also now just quite a bit slower than V8 which may contribute.