GPT OSS 20B vs GPT OSS 20B Heretic
Side-by-side comparison of VRAM requirements, quantization, context length, and hardware compatibility.
Specifications
| GPT OSS 20B | GPT OSS 20B Heretic | |
|---|---|---|
| Parameters | 21.5B | 20.9B |
| Context | 131K | 131K |
| Architecture | GptOssForCausalLM | GptOssForCausalLM |
| License | Apache 2.0 | Apache 2.0 |
| Downloads | 7.6M | 913 |
| Released | Aug 2025 | Nov 2025 |
VRAM by Quantization: GPT OSS 20B vs GPT OSS 20B Heretic
| Quantization | Bits | GPT OSS 20B VRAM | GPT OSS 20B Heretic VRAM |
|---|---|---|---|
| Q2_K | 3.40 | 9.5 GB | — |
| Q3_K_M | 3.90 | 10.9 GB | — |
| Q3_K_S | 3.50 | 9.8 GB | — |
| Q4_0 | 4.00 | 11.1 GB | — |
| Q4_K_M | 4.80 | 13.3 GB | — |
| Q5_K_M | 5.70 | 15.7 GB | — |
| Q6_K | 6.60 | 18.1 GB | — |
| Q8_0 | 8.00 | 21.9 GB | 21.3 GB |
Verdict
GPT OSS 20B Heretic needs less VRAM at Q8_0 (21.3 GB vs 21.9 GB), so it fits on smaller GPUs. GPT OSS 20B is the more widely downloaded of the two.
Frequently Asked Questions
- Which needs less VRAM, GPT OSS 20B or GPT OSS 20B Heretic?
At Q8_0, GPT OSS 20B needs 21.9 GB and GPT OSS 20B Heretic needs 21.3 GB, so GPT OSS 20B Heretic is the lighter option to run locally.
- Which has a longer context window, GPT OSS 20B or GPT OSS 20B Heretic?
GPT OSS 20B supports 131,072 tokens and GPT OSS 20B Heretic supports 131,072 tokens.
- What is the difference between GPT OSS 20B and GPT OSS 20B Heretic?
GPT OSS 20B is a 21.5B model from OpenAI (GPT-OSS family), while GPT OSS 20B Heretic is a 20.9B model from p-e-w (GPT-OSS family). Compare their VRAM requirements above to see which fits your GPU or Mac.