Bartowski·GPT-OSS

Openai GPT OSS 120B GGUF MXFP4 Experimental — Hardware Requirements & GPU Compatibility

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Based on GPT OSS 120B

Specifications

Publisher
Bartowski
Family
GPT-OSS
Parameters
120B
Release Date
2025-08-05

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How Much VRAM Does Openai GPT OSS 120B GGUF MXFP4 Experimental Need?

Select a quantization to see compatible GPUs below.

QuantizationBitsVRAM
Q2_K3.4056.1 GB
Q3_K_S3.5057.8 GB
Q3_K_M3.9064.3 GB
Q4_04.0066 GB
Q4_K_M4.8079.2 GB
Q5_K_M5.7094.0 GB
Q6_K6.60108.9 GB
Q8_08.00132 GB

Which GPUs Can Run Openai GPT OSS 120B GGUF MXFP4 Experimental?

Q4_K_M · 79.2 GB

Openai GPT OSS 120B GGUF MXFP4 Experimental (Q4_K_M) requires 79.2 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 103+ GB is recommended. No single GPU has enough memory — multi-GPU or cluster setups are needed.

Which Devices Can Run Openai GPT OSS 120B GGUF MXFP4 Experimental?

Q4_K_M · 79.2 GB

5 devices with unified memory can run Openai GPT OSS 120B GGUF MXFP4 Experimental, including NVIDIA DGX H100, NVIDIA DGX A100 640GB.

Related Models

Frequently Asked Questions

How much VRAM does Openai GPT OSS 120B GGUF MXFP4 Experimental need?

Openai GPT OSS 120B GGUF MXFP4 Experimental requires 79.2 GB of VRAM at Q4_K_M, or 132 GB at Q8_0.

VRAM = Weights + KV Cache + Overhead

Weights = 120B × 4.8 bits ÷ 8 = 72 GB

KV Cache + Overhead 7.2 GB (at 2K context + ~0.3 GB framework)

VRAM usage by quantization

79.2 GB

Learn more about VRAM estimation →

Can NVIDIA GeForce RTX 5090 run Openai GPT OSS 120B GGUF MXFP4 Experimental?

No — Openai GPT OSS 120B GGUF MXFP4 Experimental requires at least 56.1 GB at Q2_K, which exceeds the NVIDIA GeForce RTX 5090's 32 GB of VRAM.

What's the best quantization for Openai GPT OSS 120B GGUF MXFP4 Experimental?

For Openai GPT OSS 120B GGUF MXFP4 Experimental, Q4_K_M (79.2 GB) offers the best balance of quality and VRAM usage. Q5_K_S (90.8 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 56.1 GB.

VRAM requirement by quantization

Q2_K
56.1 GB
Q4_0
66.0 GB
Q4_K_S
74.3 GB
Q4_K_M
79.2 GB
Q5_K_M
94.0 GB
Q8_0
132.0 GB

★ Recommended — best balance of quality and VRAM usage.

Learn more about quantization →

Can I run Openai GPT OSS 120B GGUF MXFP4 Experimental on a Mac?

Openai GPT OSS 120B GGUF MXFP4 Experimental requires at least 56.1 GB at Q2_K, which exceeds the unified memory of most consumer Macs. You would need a Mac Studio or Mac Pro with a high-memory configuration.

Can I run Openai GPT OSS 120B GGUF MXFP4 Experimental locally?

Yes — Openai GPT OSS 120B GGUF MXFP4 Experimental can run locally on consumer hardware. At Q4_K_M quantization it needs 79.2 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.

How fast is Openai GPT OSS 120B GGUF MXFP4 Experimental?

At Q4_K_M, Openai GPT OSS 120B GGUF MXFP4 Experimental can reach ~37 tok/s on AMD Instinct MI300X. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.

tok/s = (bandwidth GB/s ÷ model GB) × efficiency

Example: AMD Instinct MI300X5300 ÷ 79.2 × 0.55 = ~37 tok/s

Estimated speed at Q4_K_M (79.2 GB)

~37 tok/s
~28 tok/s
~23 tok/s

Real-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.

Learn more about tok/s estimation →

What's the download size of Openai GPT OSS 120B GGUF MXFP4 Experimental?

At Q4_K_M, the download is about 72.00 GB. The full-precision Q8_0 version is 120.00 GB. The smallest option (Q2_K) is 51.00 GB.

Which GPUs can run Openai GPT OSS 120B GGUF MXFP4 Experimental?

No single consumer GPU has enough VRAM to run Openai GPT OSS 120B GGUF MXFP4 Experimental at Q4_K_M (79.2 GB). Multi-GPU or professional hardware is required.

Which devices can run Openai GPT OSS 120B GGUF MXFP4 Experimental?

5 devices with unified memory can run Openai GPT OSS 120B GGUF MXFP4 Experimental at Q4_K_M (79.2 GB), including Mac Pro M2 Ultra (192 GB), Mac Studio M2 Ultra (192 GB), Mac Studio M4 Max (128 GB), NVIDIA DGX A100 640GB. Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.