GPT OSS 20B RichardErkhov Heresy vs GPT OSS 120B

Side-by-side comparison of VRAM requirements, quantization, context length, and hardware compatibility.

GPT OSS 20B RichardErkhov Heresy

MuXodious · 21.5B

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GPT OSS 120B

OpenAI · 120.4B

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Specifications

GPT OSS 20B RichardErkhov HeresyGPT OSS 120B
Parameters21.5B120.4B
Context131K131K
ArchitectureGptOssForCausalLMGptOssForCausalLM
LicenseApache 2.0Apache 2.0
Downloads1814.5M
ReleasedFeb 2026Aug 2025

VRAM by Quantization: GPT OSS 20B RichardErkhov Heresy vs GPT OSS 120B

QuantizationBitsGPT OSS 20B RichardErkhov Heresy VRAMGPT OSS 120B VRAM
Q2_K3.409.5 GB51.6 GB
Q3_K_M3.9010.9 GB59.1 GB
Q3_K_S3.509.8 GB53.1 GB
Q4_04.0011.1 GB60.6 GB
Q4_K_M4.8013.3 GB72.7 GB
Q5_K_M5.7015.7 GB86.2 GB
Q6_K6.6018.1 GB99.8 GB
Q8_08.0021.9 GB120.8 GB

Verdict

GPT OSS 20B RichardErkhov Heresy needs less VRAM at Q4_K_M (13.3 GB vs 72.7 GB), so it fits on smaller GPUs. GPT OSS 120B is the more widely downloaded of the two.

Frequently Asked Questions

Which needs less VRAM, GPT OSS 20B RichardErkhov Heresy or GPT OSS 120B?

At Q4_K_M, GPT OSS 20B RichardErkhov Heresy needs 13.3 GB and GPT OSS 120B needs 72.7 GB, so GPT OSS 20B RichardErkhov Heresy is the lighter option to run locally.

Which has a longer context window, GPT OSS 20B RichardErkhov Heresy or GPT OSS 120B?

GPT OSS 20B RichardErkhov Heresy supports 131,072 tokens and GPT OSS 120B supports 131,072 tokens.

What is the difference between GPT OSS 20B RichardErkhov Heresy and GPT OSS 120B?

GPT OSS 20B RichardErkhov Heresy is a 21.5B model from MuXodious (GPT-OSS family), while GPT OSS 120B is a 120.4B model from OpenAI (GPT-OSS family). Compare their VRAM requirements above to see which fits your GPU or Mac.