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URL: https://willitrunai.com/can-run/gpt-oss-120b-on-b200-180gb


Can GPT-OSS 120B run on NVIDIA B200 180GB?

YES — Runs Great

S94Excellent
Estimated from fit model

GPT-OSS 120B needs ~95.2 GB VRAM. NVIDIA B200 180GB has 180.0 GB. With Q4_K_M quantization, expect ~94 tok/s.

Runtime: llama.cppCapacity: RoomyBandwidth: HighStack: StandardBottleneck: 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) — 95.2 GB, 102.4 tok/s, Runs well
95.2 GB required180.0 GB available
53% VRAM used

Fit status

Runs well

Decode

102.4 tok/s

TTFT

1891 ms

Safe context

131K

Memory

95.2 GB / 180.0 GB

Memory breakdown

Weights71.4 GB
KV Cache4.9 GB
Runtime0.9 GB
Headroom18.0 GB

See how fast it feels

See how fast it feelsGPT-OSS 120B on NVIDIA B200 180GB
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: 102.4 tok/s decode · 1.9s TTFT (warm) · 256 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 well102.4 tok/s1031 ms131K
CodingSRuns well94.2 tok/s2056 ms131K
Agentic CodingSRuns well102.4 tok/s2750 ms131K
ReasoningSRuns well102.4 tok/s2234 ms131K
RAGSRuns well102.4 tok/s3438 ms131K

Quantization options

How GPT-OSS 120B (117B params) fits at each quantization level on NVIDIA B200 180GB (180.0 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
45.6 GB
LowA82
Q3_K_S
3
57.3 GB
LowA83
NVFP4
4

Get started

Copy-paste commands to run GPT-OSS 120B on your machine.

Run

ollama run gpt-oss:120b

Your hardware

More models your NVIDIA B200 180GB can run

ModelParamsGradeDecodeCapabilities
👁 Mistral
Devstral 2 123B Instruct
123BS97.4 tok/s
👁 Alibaba
Qwen 3.5 122B A10B
122BS

Frequently asked questions

See all results for NVIDIA B200 180GBSee all hardware for GPT-OSS 120B
65.5 GB
Medium
A84
Q4_K_M
4
71.4 GB
MediumA85
Q5_K_M
5
84.2 GB
HighS86
Q6_K
6
95.9 GB
HighS88
Q8_0Best for your GPU
8
125.2 GB
Very HighS88
F16
16
239.8 GB
MaximumF0
270.2 tok/s
👁 DeepSeek
DeepSeek V4 Flash
284BS144.8 tok/s
👁 Mistral
Mistral Small 4 119B
119BS292.9 tok/s