Can I Run Nemotron 3 Super on 256 GB system RAM?
Written by Jakub Rusinowski · Last updated August 15, 2026
Yes — comfortably
Yes, comfortably — Nemotron 3 Super 120B-A12B at Q6_K needs about 102.1 GB of the 204.8 GB usable on 256 GB system RAM, leaving ~102.7 GB spare and running at ~5.9 tok/s (estimated), with room for about 131,072 tokens of context.
Confidence: medium · Recommended quantization: Q6_K · Estimated speed: ~5.9 tok/s
256 GB system RAM — what it gives a model
| Usable memory for models | 204.8 GB |
| Memory bandwidth | 90 GB/s |
Nemotron 3 Super on 256 GB system RAM: memory by quantization
| Quant | Memory needed | Fits 204.8 GB? | Max context | Est. speed | Download |
|---|
| F16 | 243.7 GB | ✗ No | — | — | 240 GB |
| Q8_0 | 131.2 GB | ✓ Yes | 128K | ~4.7 tok/s | 127.5 GB |
| Q6_K | 102.1 GB | ✓ Yes | 128K | ~5.9 tok/s | 98.4 GB |
| Q5_K_M | 88.7 GB | ✓ Yes | 128K | ~6.7 tok/s | 85.1 GB |
| Q4_K_M | 76.1 GB | ✓ Yes | 128K | ~7.6 tok/s | 72.5 GB |
| Q3_K_M | 54.8 GB | ✓ Yes | 128K | ~10 tok/s | 51.2 GB |
| Q2_K | 43.1 GB | ✓ Yes | 128K | ~12.2 tok/s | 39.4 GB |
What to watch out for
- This model does not publish its full attention configuration, so the KV-cache share of these figures is inferred from its parameter count rather than computed exactly.
- These figures assume CPU-only inference. Any discrete GPU, even an 8 GB one, will be several times faster for models that fit in its VRAM.
Recommended setup
llama.cpp (CPU build) or Ollama — both run without a GPU
How these numbers are calculated
- Memory need = quantized weights + KV cache at 8,192 tokens (f16) + 0.8 GB runtime overhead.
- 204.8 GB of the 256 GB is treated as usable for model weights (80% — the rest is the OS and running applications).
- DDR5-5600 dual channel at 89.6 GB/s peak. CPU decode is assumed to sustain 35% of that peak, because CPU inference is not purely bandwidth-bound — it also spends real time in compute and thread synchronisation. This figure is an assumption, not a fitted constant: no CPU measurement is in the calibration set.
- CPU-only inference: no GPU is assumed. A GPU of any size will beat these figures substantially.
- Throughput is a memory-bandwidth roofline estimate, not a measurement. It is labelled "estimated" everywhere it appears.
- KV cache is inferred from the parameter count because this model does not publish its full attention configuration.
FAQ
Can I run Nemotron 3 Super on 256 GB system RAM?
Yes, comfortably — Nemotron 3 Super 120B-A12B at Q6_K needs about 102.1 GB of the 204.8 GB usable on 256 GB system RAM, leaving ~102.7 GB spare and running at ~5.9 tok/s (estimated), with room for about 131,072 tokens of context.
Which quantization of Nemotron 3 Super should I use on 256 GB system RAM?
Q6_K — it needs about 102.1 GB of the 204.8 GB available, downloads as roughly 98.4 GB, and runs at an estimated 5.9 tokens/sec with up to 128K of context.
What limits Nemotron 3 Super on 256 GB system RAM?
Nothing binding — the model fits with headroom and generates at a usable speed on this hardware.
Which runtime should I use?
llama.cpp (CPU build) or Ollama — both run without a GPU
Other RAM Capacities
Other Models on 256 GB system RAM
Nemotron 3 Super on GPUs
What This Model Is Good At
Model & Tools
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