GPT-OSS 20B needs ~19.7 GB VRAM. RTX 5000 Ada 32GB has 32.0 GB. With Q4_K_M quantization, expect ~89 tok/s.
Operating mode
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.
Select quantization to explore
Fit status
Runs well
Decode
88.5 tok/s
TTFT
2189 ms
Safe context
97K
Memory
19.7 GB / 32.0 GB
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.
| Workload | Grade | Fit | Decode | TTFT | Context |
|---|---|---|---|---|---|
| Chat | S | Runs well | 88.5 tok/s | 1194 ms | 97K |
| Coding | S | Runs well | 88.5 tok/s | 2189 ms | 97K |
| Agentic Coding | S | Runs well | 88.5 tok/s | 3183 ms | 97K |
| Reasoning | S | Runs well | 88.5 tok/s | 2586 ms | 97K |
| RAG | S | Runs well | 88.5 tok/s | 3979 ms | 97K |
How GPT-OSS 20B (21B params) fits at each quantization level on RTX 5000 Ada 32GB (32.0 GB usable).
| Quant | Bits | VRAM | Quality | Fit |
|---|---|---|---|---|
Q2_K | 2 | 8.2 GB | Low | A84 |
Q3_K_S | 3 | 10.3 GB | Low | A85 |
NVFP4 | 4 | 11.8 GB | Medium | S85 |
Q4_K_M | 4 | 12.8 GB | Medium | S86 |
Q5_K_M | 5 | 15.1 GB | High | S87 |
Q6_K | 6 | 17.2 GB | High | S88 |
Q8_0Best for your GPU | 8 | 22.5 GB | Very High | S87 |
F16 | 16 | 43.1 GB | Maximum | F0 |
Copy-paste commands to run GPT-OSS 20B on your machine.
Run
ollama run gpt-ossYour hardware
| Model | Params | Grade | Decode | Capabilities |
|---|---|---|---|---|
| 30.5B | S | 69.7 tok/s | ||
| 27B | S | 30.2 tok/s | ||
| 27B | S | 30.3 tok/s | ||
| 35B | S | 58.6 tok/s | ||
| 30B | S | 72.1 tok/s |
Yes, RTX 5000 Ada 32GB can run GPT-OSS 20B with a S grade (Runs well). Expected decode speed: 88.5 tok/s.
GPT-OSS 20B (21B parameters) requires approximately 19.7 GB of memory with Q4_K_M quantization.
The recommended quantization for GPT-OSS 20B is Q4_K_M, which balances quality and memory efficiency.
On RTX 5000 Ada 32GB, GPT-OSS 20B achieves approximately 88.5 tokens per second decode speed with a time-to-first-token of 2189ms using Q4_K_M quantization.
For coding workloads, GPT-OSS 20B on RTX 5000 Ada 32GB receives a S grade with 88.5 tok/s and 97K context.
On RTX 5000 Ada 32GB, GPT-OSS 20B can safely use up to 97K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.
Paste this snippet into any page to show a live fit card.
<iframe src="https://willitrunai.com/embed/gpt-oss-20b-on-rtx-5000-ada-32gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>
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