# llimphi-gpu-bench

Standalone binary to validate the "direct wgpu GPU" section of
`02_ruway/llimphi/SDD.md` on a machine with a real GPU.

It does four things in order and prints everything to stdout in
copy-paste-friendly markdown/table form:

1. **System header** — version, time, OS, detected GPU.
2. **wgpu adapter info** — backend (Vulkan/Metal/DX12/GL), device name, vendor,
   relevant limits.
3. **vello vs direct GPU spike** — for N ∈ {25K, 50K, 100K, 200K, 500K, 1M}. It
   measures ms/frame for each and the factor, and evaluates the SDD's criterion:
   ≥5× at 500K → PASS; below → ABORT.
4. **Direct-GPU scaling alone** — for N ∈ {100K, 500K, 1M, 2M, 5M, 10M}. It
   measures ms/frame, equivalent fps and Mprim/s, and evaluates the 60 fps @ 1M
   goal.
5. **Visual verification PNGs** — it exports two files to the cwd:
   `bench_vello_100k.png` and `bench_directo_100k.png`. The shape of the dot sky
   must match between the two (deterministic LCG).

## Use

```sh
cargo run --release -p llimphi-gpu-bench
```

---

Part of **llimphi** — see [llimphi](../README.md).