How Much VRAM Does gpt-oss Safeguard 20B Need to Run Locally?
See devices that run itgpt-oss Safeguard 20B is a MoE model with 20.9B total parameters and 3.6B active per token. At Q4 it needs 14GB of VRAM to sit entirely on the GPU; with experts offloaded to system RAM it needs only 4GB of VRAM plus 12GB of RAM. The cheapest device that holds it is the GeForce RTX 4080, with no used-price data yet, at roughly 118.2 tokens/s. In offload mode the cheapest card that runs it is the GeForce RTX 2080 Ti, at roughly 29 tokens/s.
gpt-oss Safeguard 20B details
VRAM needed for gpt-oss Safeguard 20B by quantization and context
Total at 8KMoE: all 20.9B parameters must stay resident in memory, while speed is set by the 3.6B active per token.
| Quantization | WeightsGB | Total at 8KGB | Total at 32KGB | Total at 128KGB |
|---|---|---|---|---|
| Q4_K_M | 11.6GGUF | 13 | 14.2 | 18.7 |
| Q5_K_M | 11.7GGUF | 15.5 | 16.6 | 21.1 |
| Q8_0 | 12.1GGUF | 23 | 24.2 | 28.7 |
| FP16 | 13.8GGUF | 42.3 | 43.4 | 47.9 |
Total = weights + KV cache (FP16) + 1GB runtime overhead. Weights marked GGUF are measured file sizes from the repository; the rest are estimated from bytes per parameter. Contexts beyond this model's 128K limit show a dash.
Which GPUs can run gpt-oss Safeguard 20B?
Q4_K_M · 8K context · sorted by eBay used price| Device | VRAMGB | Used price | Est. t/s | Suggested context |
|---|---|---|---|---|
| 16 | —No listings | 118.2 | 32K | |
| 16 | —No listings | 132.1 | 32K | |
| 16 | —No listings | 136.4 | 32K | |
| 16 | —No listings | 89.5 | 32K | |
| 16 | —No listings | 90.9 | 32K | |
| 16 | —No listings | 132.4 | 32K | |
| 20 | —No listings | 104.2 | 128K | |
| 24 | —No listings | 67.1 | 128K | |
| 24 | —No listings | 134.8 | 128K | |
| 24 | —No listings | 139.4 | 128K | |
| 24 | —No listings | 156.7 | 128K | |
| 24 | —No listings | 115.4 | 128K | |
| 24 | —No listings | 114.1 | 128K | |
| 32 | —No listings | 82.1 | 128K | |
| 32 | —No listings | 82.1 | 128K | |
| 32 | —No listings | 119.8 | 128K | |
| 32 | —No listings | 172.9 | 128K | |
| 32 | —No listings | 172.9 | 128K | |
| 32 | —No listings | 130.8 | 128K | |
| 32 | —No listings | 90.9 | 128K | |
| 32 | —No listings | 84.9 | 128K | |
| 32 | —No listings | 132.1 | 128K | |
| 32 | —No listings | 132.4 | 128K | |
| 40 | —No listings | 165.1 | 128K | |
| 40 | —No listings | 165.3 | 128K | |
| 48 | —No listings | 139.4 | 128K | |
| 48 | —No listings | 108.9 | 128K | |
| 48 | —No listings | 156.7 | 128K | |
| 64 | —No listings | 162.8 | 128K | |
| 64 | —No listings | 148.5 | 128K | |
| 72 | —No listings | 156.7 | 128K | |
| 84 | —No listings | 165.6 | 128K | |
| 96 | —No listings | 172.9 | 128K | |
| Mac Studio M4 Max 128GB | 128 | —No listings | 87.3 | 128K |
| Mac Studio M5 Max 128GB | 128 | —No listings | 94.1 | 128K |
| MacBook Pro M4 Max 128GB | 128 | —No listings | 87.3 | 128K |
| MacBook Pro M5 Max 128GB | 128 | —No listings | 94.1 | 128K |
| Mac Studio M3 Ultra 512GB | 512 | —No listings | 111.5 | 128K |
Fits when weights + KV cache + runtime overhead is at or below usable memory, single card. "Offload" on MoE models means it runs with expert weights in system RAM (only attention layers and KV cache stay in VRAM); that speed assumes 70 GB/s RAM bandwidth. The context column is the largest tier that fits.
GPUs that run gpt-oss Safeguard 20B with experts offloaded to RAM
Expert weights live in system RAM (needs at least 12 GB); VRAM holds only attention layers, shared experts and the KV cache, at least 4 GB at Q4. Speed is bound by RAM bandwidth (estimated at 70 GB/s) and is far slower than a full-VRAM setup.
| Device | VRAMGB | Used price | RAM neededGB | Est. t/s |
|---|---|---|---|---|
| 11 | — | 12 | 28.8 |
Run gpt-oss Safeguard 20B with Ollama, llama.cpp or vLLM
The Ollama library has no official tag for it yet.
llama.cpp pulls the GGUF straight from Hugging Face; -c sets the context length.
llama-server -hf unsloth/gpt-oss-safeguard-20b-GGUF:Q4_K_M -c 8192
vLLM serves the original-precision weights, which needs far more memory than GGUF and usually more than one GPU.
vllm serve openai/gpt-oss-safeguard-20b
File names follow that week's model-library snapshot; the definitions are in the methodology. Methodology
FAQ
How much VRAM does gpt-oss Safeguard 20B need?
At Q4_K_M with an 8K context gpt-oss Safeguard 20B needs about 14GB of VRAM; 16GB leaves comfortable headroom.
What is the cheapest GPU that runs gpt-oss Safeguard 20B?
The GeForce RTX 4080: 16GB of VRAM at roughly 118.2 tokens/s. We have no used-price data for it yet.
Can you run gpt-oss Safeguard 20B with Ollama?
Not yet: the Ollama library has no official tag for it. You can load the GGUF with llama.cpp instead.