Best hardware for GPT-OSS 20B
21B params, 3.6B active at MXFP4 — every tracked GPU and current Mac, graded. Engine estimates, dataset updated 2026-09-03.
GPT-OSS 20B on every tracked GPU
| GPU | Memory | Verdict | Est. speed | Value | |
|---|---|---|---|---|---|
| NVIDIA GeForce RTX 5090 | 32 GB VRAM | Runs well | ~122 tok/s | 26 / $1k | Full verdict |
| NVIDIA RTX PRO 6000 Blackwell | 96 GB VRAM | Runs well | ~122 tok/s | 9 / $1k | |
| NVIDIA GeForce RTX 4090 | 24 GB VRAM | Runs well | ~87 tok/s | 25 / $1k | Full verdict |
| NVIDIA GeForce RTX 5080 | 16 GB VRAM | Runs well | ~79 tok/s | 50 / $1k | Full verdict |
| AMD Radeon RX 7900 XTX | 24 GB VRAM | Runs well | ~75 tok/s | 107 / $1k | |
| NVIDIA GeForce RTX 5070 Ti | 16 GB VRAM | Runs well | ~73 tok/s | 63 / $1k | Full verdict |
| NVIDIA GeForce RTX 3090 | 24 GB VRAM | Runs well | ~73 tok/s | 81 / $1k | Full verdict |
| NVIDIA GeForce RTX 4080 SUPER | 16 GB VRAM | Runs well | ~66 tok/s | 41 / $1k | |
| AMD Radeon RX 7900 XT | 20 GB VRAM | Runs well | ~62 tok/s | 113 / $1k | |
| NVIDIA GeForce RTX 4070 Ti SUPER | 16 GB VRAM | Runs well | ~60 tok/s | 41 / $1k | Full verdict |
| NVIDIA GeForce RTX 5060 Ti | 16 GB VRAM | Runs well | ~43 tok/s | 62 / $1k | |
| NVIDIA GeForce RTX 4060 Ti | 16 GB VRAM | Runs well | ~29 tok/s | 48 / $1k | Full verdict |
| AMD Ryzen AI Max+ 395 (Strix Halo) | 110 GB unified memory | Runs well | ~25 tok/s | 7 / $1k | |
| NVIDIA GeForce RTX 5070 | 12 GB VRAM | Tight | ~37 tok/s | 47 / $1k | |
| NVIDIA GeForce RTX 4070 SUPER | 12 GB VRAM | Tight | ~35 tok/s | 32 / $1k | |
| NVIDIA GeForce RTX 4070 | 12 GB VRAM | Tight | ~33 tok/s | 35 / $1k | Full verdict |
| NVIDIA GeForce RTX 3060 | 12 GB VRAM | Tight | ~26 tok/s | 44 / $1k | Full verdict |
| NVIDIA GeForce RTX 4060 | 8 GB VRAM | No | ~9 tok/s | — | Full verdict |
Value = est. tok/s per $1,000 at the dated median listing price. Cheapest: AMD Radeon RX 7900 XT (~$550 used).
GPT-OSS 20B on current Macs (M5/M6)
| Mac | Memory | Verdict | Est. speed | |
|---|---|---|---|---|
| Mac Mini M6 16GB | 16 GB unified memory | Tight | ~20 tok/s | |
| MacBook Air M5 24GB | 24 GB unified memory | Runs well | ~25 tok/s | |
| MacBook Pro M5 Pro 48GB | 48 GB unified memory | Runs well | ~48 tok/s | |
| MacBook Pro M5 Max 128GB | 128 GB unified memory | Runs well | ~82 tok/s | |
| Mac Studio M5 Ultra 256GB | 256 GB unified memory | Runs well | ~120 tok/s |
Unified memory: the RAM budget (~70-85%) is the limit, not a VRAM wall. Current-gen configs only.
Frequently asked questions
What is the cheapest GPU that runs GPT-OSS 20B well?
The AMD Radeon RX 7900 XT is the cheapest tracked card where GPT-OSS 20B (MXFP4) runs comfortably — ~62 tok/s estimated, at ~$550 used.
What is the best value GPU for GPT-OSS 20B?
On estimated tokens per dollar, the AMD Radeon RX 7900 XT leads for GPT-OSS 20B at ~113 tok/s per $1,000 (~$550 used). Prices are dated listing medians.
Does GPT-OSS 20B run on a Mac?
Yes. GPT-OSS 20B runs from the MacBook Air M5 24GB (~25 tok/s est.) up; unified memory means the RAM budget, not a VRAM wall, is the limit. Apple Silicon is often the cheapest path to large models.
What is the fastest way to run GPT-OSS 20B?
The fastest tracked machine for GPT-OSS 20B is the NVIDIA GeForce RTX 5090 at ~122 tok/s estimated. Speed is memory-bandwidth-bound, so high-bandwidth cards win.
Cite this page
ModelFit: Best hardware for GPT-OSS 20B (21B, MXFP4). https://modelfit.io/best-hardware-for/gpt-oss-20b/ (dataset updated 2026-09-03, CC BY 4.0).