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URL: https://willitrunai.com/can-run/gpt-oss-20b-on-a100-80gb


Can GPT-OSS 20B run on NVIDIA A100 80GB?

YES — Runs Great

S87Excellent
Estimated from fit model

GPT-OSS 20B needs ~24.5 GB VRAM. NVIDIA A100 80GB has 80.0 GB. With Q4_K_M quantization, expect ~306 tok/s.

Runtime: OllamaCapacity: RoomyBandwidth: HighStack: BasicBottleneck: Balanced
Share:

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) — 24.5 GB, 328.8 tok/s, Runs well
24.5 GB required80.0 GB available
31% VRAM used

Fit status

Runs well

Decode

328.8 tok/s

TTFT

589 ms

Safe context

128K

Memory

24.5 GB / 80.0 GB

Memory breakdown

Weights12.8 GB
KV Cache2.4 GB
Runtime1.2 GB
Headroom8.0 GB

See how fast it feels

See how fast it feelsGPT-OSS 20B on NVIDIA A100 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: 328.8 tok/s decode · 589ms TTFT (warm) · 822 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 well305.9 tok/s350 ms128K
CodingSRuns well305.9 tok/s633 ms128K
Agentic CodingSRuns well305.9 tok/s921 ms128K
ReasoningSRuns well305.9 tok/s748 ms128K
RAGSRuns well305.9 tok/s1151 ms128K

Quantization options

How GPT-OSS 20B (21B params) fits at each quantization level on NVIDIA A100 80GB (80.0 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
8.2 GB
LowA79
Q3_K_S
3
10.3 GB
LowA79
NVFP4
4

Get started

Copy-paste commands to run GPT-OSS 20B on your machine.

Run

ollama run gpt-oss

Your hardware

More models your NVIDIA A100 80GB can run

ModelParamsGradeDecodeCapabilities
👁 Mistral
Devstral 2 123B Instruct
123BA17.6 tok/s
👁 Alibaba
Qwen3-Coder 30B A3B Instruct
30.5BS

Frequently asked questions

See all results for NVIDIA A100 80GBSee all hardware for GPT-OSS 20B
11.8 GB
Medium
A79
Q4_K_M
4
12.8 GB
MediumA79
Q5_K_M
5
15.1 GB
HighA79
Q6_K
6
17.2 GB
HighA80
Q8_0
8
22.5 GB
Very HighA81
F16Best for your GPU
16
43.1 GB
MaximumS86
259 tok/s
👁 Alibaba
Qwen 3.5 27B
27BS112.3 tok/s
👁 Alibaba
Qwen 3.6 27B
27BS112.7 tok/s
👁 Alibaba
Qwen 3.5 122B A10B
122BA52.1 tok/s