Nemotron 3.5 Lightning VRAM requirements
Memory needed to run Nemotron 3.5 Lightning at every published size and quant, with an 8k context. Each figure is weights plus KV cache plus runtime buffers, from the same memory model as the VRAM calculator.
Total memory by size and quant
GB at an 8k context. Bold is the Q4_K_M column, the usual starting point.
| Size | Q8_0 | Q6_K | Q5_K_M | Q4_K_M | Q3_K_M |
|---|---|---|---|---|---|
| 30B · 3B active | 32 | 26 | 22 | 19 | 15 |
KV cache by context length
GB the context alone adds on top of the weights. Add this to a weights figure to size a longer session.
| Size | Weights at Q4_K_M | 4k ctx | 16k ctx | 32k ctx | 128k ctx |
|---|---|---|---|---|---|
| 30B · 3B active | 17 | 0.0 | 0.1 | 0.2 | 0.8 |
What each size fits on at Q4_K_M
Hardware whose memory holds the model with headroom, smallest pool first. Fits means under 85% of the pool at an 8k context. A Mac's pool is what macOS lets the GPU use - two thirds of its memory up to 32 GB, three quarters from 36 GB - not the whole of it.
- 30B · 3B activeneeds about 19 GB
Smallest: NVIDIA RTX 2080 Ti 22GB (modded) (22 GB), AMD RX 7900 XTX (24 GB), Intel Arc Pro B60 24GB (24 GB), NVIDIA A10G (24 GB), and 57 more.
On a Mac: 36 GB or more, with macOS's default GPU limit.
Frequently asked
How much VRAM does Nemotron 3.5 Lightning need?
About 19 GB at Q4_K_M with an 8k context for the 30B · 3B active model, including the KV cache and runtime buffers. Q8 needs more and Q3 less; the table above lists every rung.
Can I run Nemotron 3.5 Lightning on a 16GB GPU?
Not comfortably. Even the 30B · 3B active model needs about 19 GB at Q4_K_M with an 8k context, which is more than a 16 GB card holds with headroom. A lower quant or CPU offloading can still get it running, at a cost in quality or speed.
Can I run Nemotron 3.5 Lightning on a 24GB GPU such as an RTX 3090 or 4090?
Yes. The 30B · 3B active model needs about 19 GB at Q4_K_M with an 8k context, which fits a 24 GB card with headroom.
How are these numbers calculated?
Weights at the quant's bits per weight, plus a KV cache sized from the model's attention design for the chosen context, plus compute buffers and a fixed runtime allowance. It is the same memory model the VRAM calculator uses. A family whose attention profile is not on file is sized as plain grouped-query attention, which errs towards needing more memory.