Tiny byte-level GPT training in CUDA C++. MIT.

Linux/NixOS:

nix-build -o build/nix-result

Windows, Visual Studio 2022 C++ tools, and CUDA 13.4:

CudaArch is the GPU compute capability from NVIDIA's CUDA GPU list.

.\build\turbogpt.exe --data hn1g.txt --log-to runs/ctx4

The run stores its checkpoint at runs/ctx4/ctx4.pt, containing model, optimizer, scheduler, and trainer state. Use --load CHECKPOINT.pt to resume it.

runs/ctx4/report.json is derived from the log directory. Logs are TensorBoard-compatible: one report per batch, capped at 8Mi reports, and flushed with periodic or final checkpoints.

• hn1g after 1.5G training tokens: 2.5295 BPB.