GPU Configuration

predictor.sh automatically detects and uses available GPU acceleration.

Supported Backends

Backend	Platform	Hardware
Metal	macOS	Apple Silicon (M1/M2/M3)
CUDA	Linux/Windows	NVIDIA GPUs (RTX 20/30/40 series)
CPU	All	Fallback (slower)

Automatic Detection

When you run predictor up, it automatically detects available GPUs:

$ predictor up ./llama.gguf

Detecting hardware...
  CUDA: NVIDIA RTX 4090 (24GB VRAM) ✓

Loading model: llama-7b-q4.gguf
  Size: 3.8GB
  Loading... ████████████████████ 100%

✓ Tunnel established

Force CPU Mode

If no GPU is detected, predictor.sh requires explicit consent to run on CPU:

$ predictor up ./llama.gguf

Detecting hardware...
  CUDA: Not available (driver not found)
  Metal: Not available (not macOS)

Error: No GPU detected. Use --cpu flag to run on CPU (slower).

  predictor up ./llama.gguf --cpu

Use the --cpu flag to proceed:

predictor up ./llama.gguf --cpu

GPU Selection (Multi-GPU)

On systems with multiple GPUs, use CUDA_VISIBLE_DEVICES:

# Use only GPU 0
CUDA_VISIBLE_DEVICES=0 predictor up ./llama.gguf

# Use GPUs 0 and 1
CUDA_VISIBLE_DEVICES=0,1 predictor up ./llama.gguf

VRAM Requirements

predictor.sh checks if your GPU has enough VRAM before loading:

Error: Model requires ~16GB VRAM, but GPU has 8GB available.

Options:
  1. Use a smaller quantized model (Q4_K_M uses ~4GB)
  2. Run on CPU with --cpu flag (slower)

VRAM Calculator: https://predictor.sh/vram-calculator

Typical VRAM Usage (7B Models)

Quantization	VRAM Required
Q4_K_M	~4GB
Q5_K_M	~5GB
Q6_K	~6GB
Q8_0	~8GB
F16	~14GB

Troubleshooting

CUDA Not Detected

1. Check NVIDIA drivers:

   nvidia-smi

2. Verify CUDA installation:

   nvcc --version

3. Check for GPU visibility:

   echo $CUDA_VISIBLE_DEVICES

Metal Not Detected

Metal is only available on macOS with Apple Silicon. Intel Macs do not support Metal acceleration.

Verify your chip:

sysctl -n machdep.cpu.brand_string

Out of Memory Errors

If you see CUDA/Metal out-of-memory errors:

1. Use a smaller quantization (e.g., Q4_K_M instead of Q8_0)

2. Close other GPU-intensive applications

3. Try a smaller model

GPU Temperature

Monitor GPU temperature in the TUI:

┌─ predictor ─────────────────────────────────────────────────┐
│ 🎮 CUDA | RTX 4090 | 4.2GB/24GB VRAM | 45°C                 │

If temperature is high (>80°C), consider:

• Improving case airflow

• Reducing request concurrency

• Using a lower-power model