Running Kimi K3 on B300 SXM
Kimi K3 has 2800 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 Kimi K3 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 | 6,440 GB | does not fit | full precision, the quality reference |
| FP8 | 3,220 GB | does not fit | negligible loss on most tasks |
| NVFP4 | 1,610 GB | fits | Blackwell format, native FP4 compute |
| Q4 | 1,610 GB | fits | block quantisation, broadly supported |
Kimi K3 activates 50 billion parameters per token out of 2800 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?
Kimi K3 fits on B300 SXM only when quantised. In NVFP4, its weights take about 1,610 GB of 2,304 GB. More precise formats do not fit. 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 Kimi K3 run?
See the Kimi K3 and B300 SXM fact sheets.
How much memory does Kimi K3 need?
In NVFP4, weights take about 1,610 GB including the runtime margin. The attention cache sits on top and depends on context.
Does Kimi K3 fit on B300 SXM?
Kimi K3 fits on B300 SXM only when quantised. In NVFP4, its weights take about 1,610 GB of 2,304 GB. More precise formats do not fit.
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.