Rendering makes up 75% of compile time

[TimJentzsch]

Background: Discussion on Discord with @ChristopherBiscardi and @Elabajaba.

Bevy version

Tested on main, commit 45e454a83bffd7a496621ba77bc3429fa472733d.

System information

• Linux (Pop!_OS), Ryzen 9 9950x3d CPU
• cargo 1.96.0-nightly (888f67534 2026-03-30)

Reproduction

Run cargo clean && cargo build --timings --example 3d_scene, then inspect the generated timings file.

Mine is here for reference: https://gist.github.com/TimJentzsch/3fcc84bc8dfa261f7775ade2b2cb274b

Results

The flamegraph shows that a large part of the compilation is spent on a waterfall of rendering crates that is largely compiled sequentially.

The critical path here is:

1. bevy_render: 25.15s
2. bevy_core_pipeline: 17.04s
3. bevy_pbr: 43.61s
4. bevy_gizmos_render: 5.4s

These rendering crates sum up to 91.2s, which is 76% of the total compile time.
About half of that is bevy_pbr.

Comparison with Bevy ~0.12

The original discussion was about comparing compile times with an old Bevy version, commit 22e39c4 (v0.12) that @IceSentry benchmarked back in 2024.
On https://github.com/TimJentzsch/bevy/tree/old-bevy is a small patch of this commit (figured out by @Elabajaba) that still compiles today.

Timings on my system:

Full timings: https://gist.github.com/TimJentzsch/ae10132cc0b6b20f9b74245008183c50

Notably, the compile time is only ~17% of what it is today.
bevy_pbr takes over 17 times as long now.

Of course, it's not a fair comparison, Bevy's feature set has grown massively since then, especially with regards to rendering. But still interesting to see the differences.

[ChristopherBiscardi]

my m5 max numbers from this discussion:

• 1m16s for today's 3d_scene build
• 19s for 0.12

[mockersf]

Bevy clean compilation time since last year, when I started collecting metrics. The few times we've had big regressions, we managed to fix them, but there's still a few thousands cuts...

[hxYuki]

I have a simple snake game. numbers on 5600x is

3m55s for 0.18
6m36s for main@f4789f

It even took longer for rust-analyzer building cache.