Local AI Advisor

Can Laptop · GeForce RTX 4090 Laptop · 32 GB RAM run gpt-oss-20b?

16 GB VRAM + 32 GB RAM · 576 GB/s memory bandwidth · gpt-oss-20b has 20.9B parameters (3.6B active per token).

Short answer

Yes, excellent for chat and comfortable or better for every workload we test.

Best quantization for chat: MXFP4 (11 GB of weights) on Ollama. Generation: 100–170 tok/s, leaving about 2.8 GB free for your other apps.

How it rates for each workload

Same model and machine, different jobs. Agents and long documents send far bigger prompts than chat, so they need much more speed and memory.

WorkloadVerdictQuantGenerationFirst replyContext
Chatwith Open WebUIExcellentMXFP4100–170 tok/sunder 1 s8KDetails
Coding questionswith ContinueExcellentMXFP495–160 tok/s≈1 s16KDetails
Coding in a repositorywith AiderComfortableMXFP485–140 tok/s≈3 s32KDetails
Agentic codingwith OpenCodeComfortableMXFP480–140 tok/s≈4 s32KDetails
Long documents (64K)with Open WebUIExcellentMXFP465–110 tok/s≈15 s64KDetails

Speeds are bandwidth-based estimates; no direct benchmark exists for this pair. “First reply” is the time to read the workload’s opening prompt. How we calculate

Get it running

Copy-paste commands for the MXFP4 build with a 64K context. Ollama and llama.cpp download the file straight from Hugging Face.

ollama run hf.co/unsloth/gpt-oss-20b-GGUF:F16

Downloads 13.79 GB (F16). Ollama's default context is small: set OLLAMA_CONTEXT_LENGTH=65536 before `ollama serve` for long prompts.

Different tool, context size or workload?

These pages use typical settings. The full check models your exact setup.