willitrun·ai

Can Qwen 3.5 27B run on NVIDIA H800 80GB?

YES — Runs Great

S92Excellent
Estimated from fit model

Qwen 3.5 27B needs ~28.8 GB VRAM. NVIDIA H800 80GB has 80.0 GB. With Q4_K_M quantization, expect ~159 tok/s.

Runtime: OllamaCapacity: RoomyBandwidth: HighStack: BasicBottleneck: Balanced
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Operating mode

Choose the run profile you care about

Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.

Current mode

Balanced

Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.

Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) 28.8 GB, 159.3 tok/s, Runs well
28.8 GB required80.0 GB available
36% VRAM used

Fit status

Runs well

Decode

159.3 tok/s

TTFT

1215 ms

Safe context

131K

Memory

28.8 GB / 80.0 GB

Memory breakdown

Weights16.5 GB
KV Cache3.2 GB
Runtime1.2 GB
Headroom8.0 GB

See how fast it feels

See how fast it feelsQwen 3.5 27B on NVIDIA H800 80GB
1st promptCold start — includes initialization
>Write a Python function to sort a list
Here's a Python function that sorts a list using quicksort: def quicksort(arr): if len(arr) <= 1: return arr pivot = arr[len(arr) // 2] left = [x for x in arr if x < pivot] middle = [x for x in arr if x == pivot] right = [x for x in arr if x > pivot] return quicksort(left) + middle + quicksort(right) # Example usage numbers = [3, 6, 8, 10, 1, 2, 1] print(quicksort(numbers)) # [1, 1, 2, 3, 6, 8, 10] The algorithm picks a pivot, partitions the list into smaller, equal, and larger elements, then recursively sorts each partition and concatenates the results.
2nd promptWarm — model ready, no init overhead
>Now add type hints and a docstring
def quicksort(arr: list[int]) -> list[int]: """Sort a list using the quicksort algorithm. Args: arr: List of integers to sort. Returns: A new sorted list. """ if len(arr) <= 1: return arr pivot = arr[len(arr) // 2] left = [x for x in arr if x < pivot] middle = [x for x in arr if x == pivot] right = [x for x in arr if x > pivot] return quicksort(left) + middle + quicksort(right) Added type hints for the input and return type, plus a Google-style docstring.
Estimated: 159.3 tok/s decode · 1.2s TTFT (warm) · 398 tok/s prefill

What limits this setup

This setup is broadly balanced for this model.

No major red flags

This recommendation has enough memory headroom and acceptable estimated speed for the selected workload.

Best improvement path

Performance by workload

WorkloadGradeFitDecodeTTFTContext
ChatSRuns well159.3 tok/s663 ms131K
CodingSRuns well159.3 tok/s1215 ms131K
Agentic CodingSRuns well159.3 tok/s1767 ms131K
ReasoningSRuns well159.3 tok/s1436 ms131K
RAGSRuns well159.3 tok/s2209 ms131K

Inference speed

Qwen 3.5 27B inference speed — tokens per second by GPU & Mac

Estimated decode speed (tokens/sec) for Qwen 3.5 27B at Q4_K_M across popular GPUs and Apple Silicon, using the fastest local runtime per device. Fastest is RTX 5090 32GB at ~79 tok/s. Speed is memory-bandwidth bound, so cards that fit the whole model in VRAM run far faster than ones that offload to system RAM.

GPU / MacMemoryQuantSpeed (tok/s)Fits?
NVIDIARTX 5090 32GB
32 GBQ4_K_M78.7Fits
NVIDIARTX 4090 24GB
24 GBQ4_K_M50.2Offloads
RX 7900 XTX 24GB
24 GBQ4_K_M45.3Offloads
NVIDIARTX 3090 24GB
24 GBQ4_K_M43.0Offloads
Mac Studio M3 Ultra 256GB
256 GBQ4_K_M36.5Fits
MacBook Pro M4 Max 128GB
128 GBQ4_K_M36.1Fits
MacBook Pro M4 Max 64GB
64 GBQ4_K_M36.1Fits
Mac Studio M2 Ultra 128GB
128 GBQ4_K_M30.4Fits
Mac Studio M1 Ultra 128GB
128 GBQ4_K_M28.9Fits
MacBook Pro M4 Pro 48GB
48 GBQ4_K_M22.7Fits
MacBook Pro M3 Max 64GB
64 GBQ4_K_M15.7Fits
NVIDIARTX 4080 Super 16GB
16 GBQ4_K_M14.7Too big
MacBook Pro M1 Max 64GB
64 GBQ4_K_M14.4Fits
NVIDIARTX 4070 12GB
12 GBQ4_K_M5.2Too big
NVIDIARTX 3060 12GB
12 GBQ4_K_M3.2Too big
NVIDIARTX 4060 8GB
8 GBQ4_K_M2.0Too big

Estimates for single-stream decoding at Q4_K_M; real tokens/sec varies with prompt length, context, batch size, and runtime build. Prompt processing (prefill) is faster than the decode figures shown here.

Quantization options

How Qwen 3.5 27B (27B params) fits at each quantization level on NVIDIA H800 80GB (80.0 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
10.5 GB
LowA83
Q3_K_S
3
13.2 GB
LowA83
NVFP4
4
15.1 GB
MediumA84
Q4_K_M
4
16.5 GB
MediumA84
Q5_K_M
5
19.4 GB
HighA84
Q6_K
6
22.1 GB
HighA85
Q8_0
8
28.9 GB
Very HighS86
F16Best for your GPU
16
55.4 GB
MaximumS90

Get started

Copy-paste commands to run Qwen 3.5 27B on your machine.

Run

ollama run qwen3.5:27b

Your hardware

More models your NVIDIA H800 80GB can run

ModelParamsGradeDecodeCapabilities
MistralDevstral 2 123B Instruct123BA24.9 tok/s
AlibabaQwen3-Coder 30B A3B Instruct30.5BS367.4 tok/s

Frequently asked questions

Can NVIDIA H800 80GB run Qwen 3.5 27B?

Yes, NVIDIA H800 80GB can run Qwen 3.5 27B with a S grade (Runs well). Expected decode speed: 159.3 tok/s.

How much VRAM does Qwen 3.5 27B need?

Qwen 3.5 27B (27B parameters) requires approximately 28.8 GB of memory with Q4_K_M quantization.

What is the best quantization for Qwen 3.5 27B?

The recommended quantization for Qwen 3.5 27B is Q4_K_M, which balances quality and memory efficiency.

What speed will Qwen 3.5 27B run at on NVIDIA H800 80GB?

On NVIDIA H800 80GB, Qwen 3.5 27B achieves approximately 159.3 tokens per second decode speed with a time-to-first-token of 1215ms using Q4_K_M quantization.

Can NVIDIA H800 80GB run Qwen 3.5 27B for coding?

For coding workloads, Qwen 3.5 27B on NVIDIA H800 80GB receives a S grade with 159.3 tok/s and 131K context.

What context window can Qwen 3.5 27B use on NVIDIA H800 80GB?

On NVIDIA H800 80GB, Qwen 3.5 27B can safely use up to 131K tokens of context. The model's official context limit is 131K, but available memory constrains the safe maximum.

See all results for NVIDIA H800 80GBSee all hardware for Qwen 3.5 27B
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