Nemotron 3.5 Lightning 30B-A3B

Running Nemotron 3.5 Lightning 30B-A3B locally

At Q4_0 and 4K of context, Nemotron 3.5 Lightning 30B-A3B needs about 19.8 GB — 18.0 GB of weights, 0.02 GB of KV cache and a 1.8 GB activation buffer. The smallest cards in this index that clear that comfortably are 24 GB ones — 4 of them, from the RTX 3090 up — and 31 of the 78 cards here do. These are calculated figures, not measurements: the estimate stops counting a card as comfortable at 88% of its VRAM, which is roughly the room a desktop session needs.

What longer context costs

Going from 4K to 32K adds about 0.17 GB, taking the total to 20.0 GB. That is gentler than the parameter count suggests: only 6 of 52 layers keep a KV cache that grows with context, so the cache scales at a fraction of the usual rate. The model's native window is 256K; holding all of it at Q4_0 would need about 21 GB.

Which build to download

This index only tracks Nemotron 3.5 Lightning 30B-A3B in GGUF, across 2 levels (Q4_0, Q8_0). No per-level perplexity sweep has been published for this model, so the quality column is empty rather than estimated — within one model, more bits per weight is the only ordering the data supports. No throughput has been measured for this model on this site's hardware. GGUF runs on llama.cpp and Ollama across NVIDIA, AMD and Apple silicon; AWQ and GPTQ target vLLM on CUDA and ROCm; EXL2 is ExLlamaV2 — CUDA only, and now archived, so local use rather than serving.

Common questions

How much VRAM does Nemotron 3.5 Lightning 30B-A3B need?

About 19.8 GB at Q4_0 with 4K of context and batch 1, rising to roughly 20.0 GB at 32K. That figure is weights plus KV cache plus a 10% activation buffer, calculated from the model's architecture rather than measured on a card.

Will Nemotron 3.5 Lightning 30B-A3B run on a 24GB GPU?

Yes — at Q4_0 and 4K context it needs about 19.8 GB, which leaves 4.2 GB spare on a RTX 3090, or on any of the other 24 GB cards here (4 in all). That is the smallest size in this index that clears it comfortably; 31 of 78 do.

Which quantization of Nemotron 3.5 Lightning 30B-A3B should I use?

No published quality comparison exists for this model, so pick by footprint: Q4_0 is the 4-bit build this page is sized at, and a higher bits-per-weight level is more faithful. All 2 levels in the index are Q4_0, Q8_0. Note this is a mixture-of-experts model — all parameters must be resident even though only a fraction are active per token, so the memory cost follows the total, not the active count.