pub async fn gpu_vram_bytes() -> Option<u64>Expand description
Total GPU VRAM in bytes (best-effort), or None if no GPU is detected.
On unified-memory Macs there is no separate, slow “RAM offload” target, so
system RAM is the GPU budget. On NVIDIA we read nvidia-smi. Everything
else (AMD, integrated, headless) returns None and the caller uses the
conservative fallback cap. Cached for the process.