SmolLM2 360M Instruct on an H100 80GB (SXM5)
Yes — the unquantized weights fit with room for 8k tokens of context.
Verdict
Fits at FP16
73.6 GiB usable of 80 GB
Weights (Q4_K_M)
258 MiB
690 MiB at FP16 · 362M params · 6 of 6 quant rows are measured files
KV cache
40.0 KiB per token at FP16
32 layers × 5 KV heads × 64 dimensions
Speed ceiling
3163 tok/s
3350 GB/s ÷ bytes read per token
Every quant, against this card
Weight bytes are the size of the real published file wherever one exists — 6 of these6 rows are measured from bartowski/SmolLM2-360M-Instruct-GGUF, the rest computed from the parameter count. Max context is what the KV cache can grow to in whatever memory the weights leave behind, capped at the 8k tokens this model was trained to address.
| Precision | Bits/weight | Weights | Source | Fits | Max context | Ceiling |
|---|---|---|---|---|---|---|
| FP16 / BF16 | 16.00 | 690 MiB | measured file | yes | 8,192 (model cap) | 3163 tok/s |
| Q8_0 | 8.54 | 369 MiB | measured file | yes | 8,192 (model cap) | 4640 tok/s |
| Q6_K | 8.12 | 350 MiB | measured file | yes | 8,192 (model cap) | 4766 tok/s |
| Q5_K_M | 6.41 | 277 MiB | measured file | yes | 8,192 (model cap) | 5356 tok/s |
| Q4_K_M | 5.98 | 258 MiB | measured file | yes | 8,192 (model cap) | 5527 tok/s |
| Q3_K_M | 5.19 | 224 MiB | measured file | yes | 8,192 (model cap) | 5875 tok/s |
What the context actually costs
The KV cache is 2 · layers · kv_heads · head_dim bytes per token per element — 2 · 32 · 5 · 64 · 2 B = 40.0 KiB. It depends on the key/value head count, not the attention-head count and not the parameter count. This model shares 5 KV heads across 15 query heads, which divides the cache by 3 against multi-head attention.
| Context | KV cache (FP16) | KV cache (8-bit) | Plus Q4_K_M weights |
|---|---|---|---|
| 4,096 | 160 MiB | 80 MiB | 418 MiB |
| 8,192 | 320 MiB | 160 MiB | 578 MiB |
The speed ceiling, and where it comes from
Generating one token reads every active weight from memory once. At FP16 / BF16 that is 690 MiB, plus a pass over the KV cache. An H100 80GB (SXM5) moves 3350 GB/s, so the arithmetic ceiling is 3163 tok/s. Treat it as a bound, not an estimate: attention overhead, kernel launches and imperfect memory access keep real runtimes at roughly 60–80% of it, and nothing pushes past it.
Where these numbers come from
The model
- Parameters
- 361,821,120
- Layers
- 32
- Attention / KV heads
- 15 / 5
- Head dimension
- 64
- Trained context
- 8,192
- Checkpoint as published
- 690 MiB
Read from HuggingFaceTB/SmolLM2-360M-Instruct. The parameter count is the Hub's own total over the tensor shapes, not a figure taken from the model's name.
The accelerator
- Memory
- 80 GB HBM3
- Bandwidth
- 3350 GB/s
- Assumed usable
- 92% → 73.6 GiB
Capacity and bandwidth from the vendor's specification. The usable fraction is an assumption, not a spec: a driver context, compute workspace and any attached display come out of the same pool before a weight is loaded.
Questions this pairing answers
How much VRAM does SmolLM2 360M Instruct need?
690 MiB for the weights at FP16 — 362M parameters at two bytes each — and 258 MiB at Q4_K_M. The KV cache is on top of that and is not a fixed number: this model spends 40.0 KiB per token of context, so 8,192 tokens costs a further 320 MiB. An H100 80GB (SXM5) makes 73.6 GiB of its 80 GB available on the assumption below.
Can an H100 80GB (SXM5) run SmolLM2 360M Instruct?
Yes — the unquantized weights fit with room for 8k tokens of context. That is the weights and the KV cache together, against 73.6 GiB of usable memory.
How fast will SmolLM2 360M Instruct run on an H100 80GB (SXM5)?
No faster than 3163 tokens/second at FP16 / BF16, and in practice below it. Decoding is memory-bound: every token reads all 690 MiB of weights plus the cache, and this card moves 3350 GB/s. That division is the ceiling — no kernel, runtime or driver beats it, and a real runtime typically reaches 60–80% of it.
Why does the context length change how much memory SmolLM2 360M Instruct needs?
Because the KV cache holds one key and one value vector per token, per layer, for the whole conversation, and it is allocated separately from the weights. This model has 32 layers and 5 key/value heads of 64 dimensions, shared across 15 query heads — grouped-query attention, which divides the cache by 3. That works out at 40.0 KiB per token. Parameter count tells you nothing about this number.
The same model on a different card
- A100 80GB (SXM)FP16 / BF16
- Jetson AGX Orin (64GB)FP16 / BF16
- RTX 6000 Ada GenerationFP16 / BF16
- L40SFP16 / BF16
- Apple M4 Pro (48GB)FP16 / BF16
- A100 40GB (SXM)FP16 / BF16
- GeForce RTX 5090FP16 / BF16
- Apple M4 Max (128GB)FP16 / BF16
A different model on the same card
All 62 models on H100 80GB (SXM5) →- Qwen2.5 0.5B InstructFP16 / BF16
- SmolLM2 135M InstructFP16 / BF16
- Qwen3 0.6BFP16 / BF16
- Gemma 3 1B InstructFP16 / BF16
- MiniCPM5 1BFP16 / BF16
- TinyLlama 1.1B ChatFP16 / BF16
- Llama 3.2 1B InstructFP16 / BF16
- Qwen2.5 1.5B InstructFP16 / BF16
Method and limits. Weight bytes are the byte size of the real published file wherever one exists, and the model's exact parameter count times the published llama.cpp bits-per-weight where it does not. That distinction is on every row above and it matters at both ends: a sub-1B model's Q4_K_M file runs a third larger than the nominal figure because k-quants keep its embedding tables at higher precision, and an already-4-bit release cannot be quantized upward at all. The KV cache is 2 · layers · kv_heads · head_dim · bytes per token, summed over layers with each sliding-window layer capped at its window. The speed figure is a roofline bound, not a benchmark: bandwidth divided by bytes read per token, which no runtime exceeds and every runtime falls short of. The usable fraction of card memory is an assumption: 92% here, which is what this lane assumes for a dedicated card — the other class assumes 75%, so it is not one number applied to every device. That is the only assumed input on this page; every other figure is computed from the model config and the card's published specification. Nothing on this page is written by a language model. Architecture from the model's published config, fetched 2026-08-07.