Running Nemotron 3 Ultra on B300 SXM
Nemotron 3 Ultra has 550 billion parameters. B300 SXM offers 2,304 GB of HBM3e across 8 GPUs memory. This page puts the two side by side.
How much memory does Nemotron 3 Ultra need?
Weights take the parameter count multiplied by the format size, plus a 15% runtime margin for activations and buffers. The attention cache sits on top: it grows with context length and with the number of concurrent requests, so it is sized case by case.
| Format | Weights in memory | On this machine | What the format costs |
|---|---|---|---|
| FP16 | 1,265 GB | fits | full precision, the quality reference |
| FP8 | 632 GB | fits | negligible loss on most tasks |
| NVFP4 | 316 GB | fits | Blackwell format, native FP4 compute |
| Q4 | 316 GB | fits | block quantisation, broadly supported |
Nemotron 3 Ultra activates 55 billion parameters per token out of 550 billion. Active parameters govern speed, not footprint: every expert stays resident in memory. Confusing the two under-sizes the machine by an order of magnitude.
What is left to serve requests?
Nemotron 3 Ultra fits comfortably on B300 SXM. In FP16, its weights take about 1,265 GB of the 2,304 GB available, leaving 1,039 GB for the attention cache and concurrency. The remaining margin decides how many concurrent requests and how much context the machine sustains. A margin below a quarter of memory forces a limit on context or on concurrency.
B300 SXM ranges from 500 to 800 k€, indicative and not contractual. The machine targets the GE segment.
Where else can Nemotron 3 Ultra run?
- Nemotron 3 Ultra on Mac Studio Ultra
- Nemotron 3 Ultra on DGX Station
- Nemotron 3 Ultra on RTX PRO 6000 server
- Nemotron 3 Ultra on H200 SXM server
- Nemotron 3 Ultra on B200 SXM
See the Nemotron 3 Ultra and B300 SXM fact sheets.
How much memory does Nemotron 3 Ultra need?
In FP16, weights take about 1,265 GB including the runtime margin. The attention cache sits on top and depends on context.
Does Nemotron 3 Ultra fit on B300 SXM?
Nemotron 3 Ultra fits comfortably on B300 SXM. In FP16, its weights take about 1,265 GB of the 2,304 GB available, leaving 1,039 GB for the attention cache and concurrency.
Method
Parameter counts and memory figures come from the site fact sheets. Memory footprints are calculated, not measured: a reading on real hardware may differ depending on the engine and the exact weight format. Prices are indicative and not contractual.