Published · Phase 2
llama.cpp on DGX Spark
Use llama.cpp on DGX Spark for GGUF models, local experimentation, aggressive quantization, and the least operational friction. Prefer vLLM/NIM when the goal is a high-throughput multi-user API rather than a flexible local runtime.
Editorial review: complete · Updated 2026-08-30
Plain-English answer
Plain-English answer guidance: Use llama.cpp on DGX Spark for GGUF models, local experimentation, aggressive quantization, and the least operational friction. Prefer vLLM/NIM when the goal is a high-throughput multi-user API rather than a flexible local runtime.
Why it matters
Why it matters guidance: Recommended for private chat, model evaluation, GGUF collections, and users who value transparent CLI controls. Less suitable for large concurrent fleets without an additional serving layer. Quantized KV cache is useful for very long prompts, but Q8 is the conservative default and Q4 should be validated against your task quality.
Real StackBench examples
| Configuration | Evidence state | Metric | Source |
|---|---|---|---|
| gpt-oss-120B · NVIDIA DGX Spark · llama.cpp | Source-reported · Grade C | 55.67 tokens/second | ggml-org llama.cpp DGX Spark benchmark |
Common misconception
Common misconception guidance: Feature support for brand-new architectures may be incomplete, and continuous batching is less turnkey than vLLM. Requantizing an already quantized model can degrade quality more than a clean conversion from higher precision.
Measured / example table
| Configuration | Evidence state | Metric | Source |
|---|---|---|---|
| gpt-oss-120B · NVIDIA DGX Spark · llama.cpp | Source-reported · Grade C | 55.67 tokens/second | ggml-org llama.cpp DGX Spark benchmark |
Decision rule
Decision rule guidance: Choose llama.cpp if the model is distributed as GGUF or you need quantization/offload control. Choose vLLM if throughput, batching, and API compatibility dominate.
Related benchmarks
Related benchmarks guidance: Decode on Spark is usually memory-bandwidth bound. gpt-oss-120b public results above 50 tok/s show that sparse optimized models can be quick, while dense or giant MoE checkpoints may sit in the teens or low tens. vLLM is the production-serving alternative; NIM/TensorRT-LLM is the NVIDIA-optimized alternative; Ollama/LM Studio can wrap llama.cpp for a simpler UI.
Planner / Explore CTA
Compare this recommendation against your model, context, concurrency, latency, and budget in the ComputeSage Planner.
Sources / methodology
Recommendations combine official specifications, public model/runtime documentation, adjacent benchmark observations, and clearly labeled engineering estimates. Review the ComputeSage evidence methodology.