Can I Run GPT-OSS on NVIDIA A100 80GB (PCIe)?
Written by Jakub Rusinowski · Last updated August 15, 2026
Yes, comfortably — GPT-OSS 120B at Q4_K_M needs 71.6 GB at 8K context (70.5 GB weights + 1.1 GB KV cache/overhead), leaving ~8.4 GB of the NVIDIA A100 80GB (PCIe)'s 80 GB, at ~202 tok/s (est.), with room for up to 128K context.
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NVIDIA A100 80GB (PCIe) Specs
| VRAM | 80 GB |
| Memory Bandwidth | 1935 GB/s |
GPT-OSS 120B on the NVIDIA A100 80GB (PCIe): VRAM by quantization
| Quant | VRAM needed | Fits 80 GB? | Max context | Whole PC |
|---|---|---|---|---|
| F16 | 234.7 GB | ✗ No | — | — |
| Q8_0 | 125.2 GB | ✗ No | — | — |
| Q6_K | 96.9 GB | ✗ No | — | — |
| Q5_K_M | 83.9 GB | ✗ No | — | — |
| Q4_K_M | 71.6 GB | ✓ Yes | 128K | — |
| Q3_K_M | 50.9 GB | ✓ Yes | 128K | — |
| Q2_K | 39.5 GB | ✓ Yes | 128K | — |
Assumes an 8K-token context with an f16 KV cache. A longer window needs more; a quantized KV cache needs less. “Max context” is the largest window that still fits in 80 GB. Figures are estimates from parameter count, quantization and memory bandwidth — the analyzer lets you tune KV-cache quant and context.
Context costs VRAM too. At Q4_K_M on the NVIDIA A100 80GB (PCIe): 8K 71.6 GB · 32K 72.6 GB · 128K 76.2 GB. Every window this model publishes still fits 80 GB.
No compatible GPU? GPT-OSS 120B on 96 GB of system RAM, CPU only: runs, but it is tight.
GPT-OSS Sizes That Fit the NVIDIA A100 80GB (PCIe) (at 8K context)
| GPT-OSS 120B | Q4_K_M · 71.6 GB at 8K context · ~202 tok/s (est.) |
| GPT-OSS 20B | MXFP4 · 12.1 GB at 8K context · ~254 tok/s (est.) |
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FAQ
GPT-OSS on the NVIDIA A100 80GB (PCIe) — does it fit?
Yes, comfortably — GPT-OSS 120B at Q4_K_M needs 71.6 GB at 8K context (70.5 GB weights + 1.1 GB KV cache/overhead), leaving ~8.4 GB of the NVIDIA A100 80GB (PCIe)'s 80 GB, at ~202 tok/s (est.), with room for up to 128K context.
Which GPT-OSS variant fits best on the NVIDIA A100 80GB (PCIe)?
GPT-OSS 120B at Q4_K_M quantization needs 71.6 GB at 8K context (70.5 GB weights + 1.1 GB KV cache/overhead), estimated ~202 tokens/sec, up to 128K context.
Every GPT-OSS size on the NVIDIA A100 80GB (PCIe)
| Size | VRAM at 8K | Verdict | Speed |
|---|---|---|---|
| GPT-OSS 120B | 71.6 GB | Runs | ~202 tok/s |
| GPT-OSS 20B | 12.1 GB | Runs | ~254 tok/s |
GPT-OSS on Other GPUs
Popular Models on the NVIDIA A100 80GB (PCIe)
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