Model benchmarks

gpt-oss-20b-UD-Q8_K_XL local LLM performance

As of September 2026, gpt-oss-20b-UD-Q8_K_XL runs at up to 159.6 tok/s for local inference (best of 2 community benchmark runs across 1 GPU).

llama.cppQ8_K
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Model size

20B

Peak speed

159.6 tok/s

Average speed

134.5 tok/s

Avg prefill

2069.0 tok/s

Min memory

19.5 GB

Max context

131,072 tokens

Avg output / run

15,070 tokens

Avg runtime / run

1m 49s

Avg quality

74.8

Benchmark runs

2

GPUs tested

1

Quality by task

Average LLM-judged quality (0–100) with the run-to-run spread shown as a P5–P95 band, overall and for each benchmark task, across all 2 runs. The low and high columns show how much the judge’s score varies between runs, and need at least two runs to display.

TaskP5 (low)AvgP95 (high)
Overall73.874.875.8
Agent Workflow80.381.883.3
Code Generation67.167.768.3
Role Play & Narrative74.074.374.7
Research & Analysis70.175.380.5

Performance by hardware and tool

Every hardware/tool/quantization combination gpt-oss-20b-UD-Q8_K_XL has been benchmarked on, ranked by peak token generation speed. Last updated September 2026.

HardwareToolQuantBest tok/sAvg tok/sMemoryContextQualityRuns
NVIDIA GeForce RTX 5060llama.cppQ8_K159.6 tok/s134.5 tok/s19.5 GB131,072 tokens74.82

Frequently asked questions

Is gpt-oss-20b-UD-Q8_K_XL good for coding?
In our benchmarks, gpt-oss-20b-UD-Q8_K_XL scores 67.7/100 for coding. It runs at about 134.5 tok/s, so if you want more speed, Qwen3.6-35B-A3B-Q4_K_XL is faster (~156.9 tok/s) and still scores well for coding (82.2/100).
Is gpt-oss-20b-UD-Q8_K_XL good for agentic (tool-using) tasks?
In our benchmarks, gpt-oss-20b-UD-Q8_K_XL scores 81.8/100 for agentic workflows. It runs at about 134.5 tok/s, so if you want more speed, Tiel-Coder-35B-A3B-Q4_K_S is faster (~165.0 tok/s) and still scores well for agentic workflows (89.3/100).
How fast is gpt-oss-20b-UD-Q8_K_XL for local inference?
Across 2 community benchmark runs, gpt-oss-20b-UD-Q8_K_XL reaches up to 159.6 tok/s and averages 134.5 tok/s, with the fastest results on NVIDIA GeForce RTX 5060.
How much memory does gpt-oss-20b-UD-Q8_K_XL need?
The leanest observed configuration used about 19.5 GB of memory (quantizations tested: Q8_K).
Which tools have been used to run gpt-oss-20b-UD-Q8_K_XL?
Benchmarks were submitted using llama.cpp. Results are community-contributed and updated as new runs arrive.