GPT OSS 20B vs Qwen3.6 35B A3B

Qwen3.6 35B A3B leads llmrun Score 106.9 to 96.2; both fit 24 GB at Q4_K_M; GPT OSS 20B is 1.3× faster on RTX 4090 (~190 vs ~151 tok/s).

Model A · OpenAI

GPT OSS 20B

96.2llmrun Score

20.9B · 4.2B active · 128K context · Apache 2.0 · Aug 2025

ChatFunctions

Model B · Alibaba

Qwen3.6 35B A3B

106.9llmrun Score

36.0B · 4.7B active · 256K context · Apache 2.0 · Apr 2026

VisionFunctions

Which should you choose?

Choose GPT OSS 20B if you want…

Fits a 12 GB GPU
IQ4_XS · 11.8 GB; Qwen3.6 35B A3B needs 10.4 GB at its smallest quant
1.3× faster on RTX 4090
~190 vs ~151 tok/s
Lighter on memory
12.9 vs 22.0 GB at Q4_K_M
Also does chat
Qwen3.6 35B A3B doesn't list it

Choose Qwen3.6 35B A3B if you want…

Higher llmrun Score
106.9 vs 96.2
Stronger at science
109.9 vs 92.4
Stronger at reasoning
106.6 vs 90.8
Ahead on the benchmarks
7 of 9 shared boards
Longer context window
256K vs 128K tokens
Also does vision
GPT OSS 20B doesn't list it

On your hardware

Each model at its default quant (Q4_K_M), a smaller one when it must. Estimates, ±20%.

MemoryGPT OSS 20BQwen3.6 35B A3B

8 GB

RTX 4060 · 8 GB tier

GPT OSS 20B

IQ2_M · ~103 tok/s

7.6 GB · up to 32Kfits

Qwen3.6 35B A3B

Doesn't fit

smallest quant needs 10.4 GB

12 GB

RTX 3060 12GB · 12 GB tier

GPT OSS 20B

IQ4_XS · ~89 tok/s

11.8 GB · up to 16Kbetter quant

Qwen3.6 35B A3B

IQ2_S · ~114 tok/s

11.7 GB · up to 32K

16 GB

RTX 5060 Ti 16GB · 16 GB tier

GPT OSS 20B

Q4_K_M · ~98 tok/s

13.1 GB · up to 128Kmore headroom

Qwen3.6 35B A3B

Q2_K · ~108 tok/s

15.7 GB · up to 32K

24 GBreference

RTX 4090 · 24 GB tier

GPT OSS 20B

Q4_K_M · ~190 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~151 tok/s

22 GB · up to 128K

32 GB

RTX 5090 · 32 GB tier

GPT OSS 20B

Q4_K_M · ~282 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~213 tok/s

22 GB · up to 256K

48 GB

RTX A6000 · 48 GB tier

GPT OSS 20B

Q4_K_M · ~154 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~125 tok/s

22 GB · up to 256K

Mac 32 GB

Mac Mini M4 · Macs

GPT OSS 20B

Q4_K_M · ~28 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~24 tok/s

22 GB · up to 256K

Mac 64 GB

Mac Studio M4 Max · Macs

GPT OSS 20B

Q4_K_M · ~86 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~64 tok/s

22 GB · up to 256K

Mac 128 GB

Mac Studio M4 Max · Macs

GPT OSS 20B

Q4_K_M · ~86 tok/s

13.1 GB · up to 128Kfaster

Qwen3.6 35B A3B

Q4_K_M · ~64 tok/s

22 GB · up to 256K

Reference GPU: RTX 4090. Tinted cell = the better pick on that machine (fits, more headroom, or at least 10% faster).

llmrun Score

with its 90% range · bars share one scale

GPT OSS 20B Qwen3.6 35B A3B

Overall

GPT OSS 20B

96.293–99

Qwen3.6 35B A3B

106.9104–110

Coding

GPT OSS 20B

100.992–110

Qwen3.6 35B A3B

105.299–112

Math

GPT OSS 20B

no data

Qwen3.6 35B A3B

109.0104–114

Science

GPT OSS 20B

92.485–100

Qwen3.6 35B A3B

109.9101–119

Reasoning

GPT OSS 20B

90.882–99

Qwen3.6 35B A3B

106.699–114

GPT OSS 20B · #58 of 92 open models · #15 of 34 that fit 24 GB

Qwen3.6 35B A3B · #33 of 92 open models · #3 of 34 that fit 24 GB

Benchmarks

9 shared boards: GPT OSS 20B leads 2, Qwen3.6 35B A3B leads 7 · Benchmarks imported Oct 2026

BoardGPT OSS 20BQwen3.6 35B A3B

GPQA Diamond

GPT OSS 20B

60.8%#41/97 open

IndependentEpoch AI · Aug 2025

Qwen3.6 35B A3B

84.9%#20/97 open

IndependentEpoch AI · Apr 2026

AIME 2024/2025

GPT OSS 20B

65.3%#33/85 open

IndependentEpoch AI · Aug 2025

Qwen3.6 35B A3B

86.7%#19/85 open

IndependentEpoch AI · Apr 2026

Terminal-Bench

GPT OSS 20B

3.4%#16/16 open

Lab-reportedEpoch AI · Aug 2025

Qwen3.6 35B A3B

23.0%#13/16 open

Lab-reportedEpoch AI · Apr 2026

SciCode

GPT OSS 20B

34.4%#47/65 open

Lab-reportedEpoch AI · Aug 2025

Qwen3.6 35B A3B

35.8%#41/65 open

Lab-reportedEpoch AI · Apr 2026

WeirdML

GPT OSS 20B

40.9%#21/46 open

IndependentEpoch AI · Aug 2025

Qwen3.6 35B A3B

34.5%#35/46 open

IndependentEpoch AI · Apr 2026

Chess Puzzles

GPT OSS 20B

4.0%#33/67 open

IndependentEpoch AI · Aug 2025

Qwen3.6 35B A3B

26.0%#5/67 open

IndependentEpoch AI · Apr 2026

CritPt

GPT OSS 20B

1.4%#30/65 open

Lab-reportedEpoch AI · Aug 2025

Qwen3.6 35B A3B

0.3%#44/65 open

Lab-reportedEpoch AI · Apr 2026

DTBench

GPT OSS 20B

68.0%#34/68 open

Lab-reportedEpoch AI · Aug 2025

Qwen3.6 35B A3B

73.9%#30/68 open

Lab-reportedEpoch AI · Apr 2026

LMCA

GPT OSS 20B

14.5%#43/54 open

Lab-reportedEpoch AI · Aug 2025

Qwen3.6 35B A3B

29.7%#19/54 open

Lab-reportedEpoch AI · Apr 2026

6 more boards (other shared and single-model boards)

Only GPT OSS 20B (3)

Only Qwen3.6 35B A3B (3)

VRAM by quantization

Memory to load the model and 2K context; below it, the total at 32K and 128K context. Lighter side in bold.

QuantGPT OSS 20BQwen3.6 35B A3B

Q2_K

GPT OSS 20B

9.3 GB11.5 GB file

32K 9.8 GB · 128K 11.5 GB

Qwen3.6 35B A3B

15.7 GB13.5 GB file

32K 15.9 GB · 128K 16.9 GB

Q3_K_S

GPT OSS 20B

9.5 GB11.5 GB file

32K 10.0 GB · 128K 11.7 GB

Qwen3.6 35B A3B

16.1 GB15.4 GB file

32K 16.4 GB · 128K 17.4 GB

Q3_K_M

GPT OSS 20B

10.6 GB11.5 GB file

32K 11.1 GB · 128K 12.8 GB

Qwen3.6 35B A3B

17.9 GB16.6 GB file

32K 18.2 GB · 128K 19.2 GB

Q4_0

GPT OSS 20B

10.8 GB11.5 GB file

32K 11.3 GB · 128K 13.0 GB

Qwen3.6 35B A3B

18.4 GB~18.0 GB file

32K 18.6 GB · 128K 19.6 GB

Q4_K_M

GPT OSS 20B

12.9 GB11.6 GB file

32K 13.4 GB · 128K 15.1 GB

Qwen3.6 35B A3B

22.0 GB22.1 GB file

32K 22.2 GB · 128K 23.2 GB

Q5_K_M

GPT OSS 20B

15.3 GB11.7 GB file

32K 15.8 GB · 128K 17.5 GB

Qwen3.6 35B A3B

26.0 GB26.5 GB file

32K 26.3 GB · 128K 27.3 GB

Q6_K

GPT OSS 20B

17.6 GB12.0 GB file

32K 18.1 GB · 128K 19.8 GB

Qwen3.6 35B A3B

30.0 GB29.3 GB file

32K 30.3 GB · 128K 31.3 GB

Q8_0

GPT OSS 20B

21.3 GB~20.9 GB file

32K 21.8 GB · 128K 23.5 GB

Qwen3.6 35B A3B

36.3 GB36.9 GB file

32K 36.6 GB · 128K 37.6 GB

20 more quants

IQ2_XXS

GPT OSS 20B

6.1 GB~5.8 GB file

32K 6.6 GB · 128K 8.3 GB

Qwen3.6 35B A3B

10.3 GB10.8 GB file

32K 10.5 GB · 128K 11.5 GB

IQ2_XS

GPT OSS 20B

6.7 GB~6.3 GB file

32K 7.2 GB · 128K 8.9 GB

Qwen3.6 35B A3B

11.2 GB11.7 GB file

32K 11.4 GB · 128K 12.4 GB

IQ2_S

GPT OSS 20B

6.9 GB~6.5 GB file

32K 7.4 GB · 128K 9.1 GB

Qwen3.6 35B A3B

11.6 GB11.9 GB file

32K 11.9 GB · 128K 12.9 GB

IQ2_M

GPT OSS 20B

7.4 GB~7.1 GB file

32K 7.9 GB · 128K 9.6 GB

Qwen3.6 35B A3B

12.5 GB11.5 GB file

32K 12.8 GB · 128K 13.8 GB

IQ3_XXS

GPT OSS 20B

8.5 GB11.6 GB file

32K 9.0 GB · 128K 10.7 GB

Qwen3.6 35B A3B

14.3 GB13.2 GB file

32K 14.6 GB · 128K 15.6 GB

Q2_K_S

GPT OSS 20B

8.7 GB12.1 GB file

32K 9.2 GB · 128K 10.9 GB

Qwen3.6 35B A3B

14.8 GB12.2 GB file

32K 15.0 GB · 128K 16.0 GB

IQ3_XS

GPT OSS 20B

9.0 GB11.6 GB file

32K 9.5 GB · 128K 11.2 GB

Qwen3.6 35B A3B

15.2 GB17.1 GB file

32K 15.5 GB · 128K 16.5 GB

IQ3_S

GPT OSS 20B

9.3 GB12.1 GB file

32K 9.8 GB · 128K 11.5 GB

Qwen3.6 35B A3B

15.7 GB13.7 GB file

32K 15.9 GB · 128K 16.9 GB

IQ3_M

GPT OSS 20B

9.8 GB11.6 GB file

32K 10.3 GB · 128K 12.0 GB

Qwen3.6 35B A3B

16.6 GB17.8 GB file

32K 16.8 GB · 128K 17.8 GB

Q3_K_L

GPT OSS 20B

11.1 GB11.5 GB file

32K 11.6 GB · 128K 13.3 GB

Qwen3.6 35B A3B

18.8 GB17.8 GB file

32K 19.1 GB · 128K 20.1 GB

IQ4_XS

GPT OSS 20B

11.6 GB11.6 GB file

32K 12.1 GB · 128K 13.8 GB

Qwen3.6 35B A3B

19.7 GB17.7 GB file

32K 20.0 GB · 128K 21.0 GB

IQ4_NL

GPT OSS 20B

12.1 GB11.6 GB file

32K 12.6 GB · 128K 14.3 GB

Qwen3.6 35B A3B

20.6 GB18.0 GB file

32K 20.9 GB · 128K 21.9 GB

Q4_1

GPT OSS 20B

12.1 GB11.6 GB file

32K 12.6 GB · 128K 14.3 GB

Qwen3.6 35B A3B

20.6 GB22.9 GB file

32K 20.9 GB · 128K 21.9 GB

Q4_K_S

GPT OSS 20B

12.1 GB11.6 GB file

32K 12.6 GB · 128K 14.3 GB

Qwen3.6 35B A3B

20.6 GB20.9 GB file

32K 20.9 GB · 128K 21.9 GB

Q4_K_L

GPT OSS 20B

13.2 GB11.9 GB file

32K 13.7 GB · 128K 15.4 GB

Qwen3.6 35B A3B

22.4 GB22.7 GB file

32K 22.7 GB · 128K 23.7 GB

Q5_0

GPT OSS 20B

not listed

Qwen3.6 35B A3B

22.9 GB24.1 GB file

32K 23.1 GB · 128K 24.1 GB

Q5_1

GPT OSS 20B

not listed

Qwen3.6 35B A3B

25.1 GB26.1 GB file

32K 25.4 GB · 128K 26.4 GB

Q5_K_S

GPT OSS 20B

14.8 GB11.7 GB file

32K 15.3 GB · 128K 17.0 GB

Qwen3.6 35B A3B

25.1 GB24.9 GB file

32K 25.4 GB · 128K 26.4 GB

Q5_K_L

GPT OSS 20B

15.5 GB11.9 GB file

32K 16.0 GB · 128K 17.7 GB

Qwen3.6 35B A3B

26.5 GB26.2 GB file

32K 26.7 GB · 128K 27.7 GB

BF16

GPT OSS 20B

42.2 GB~41.8 GB file

32K 42.7 GB · 128K 44.4 GB

Qwen3.6 35B A3B

72.3 GB69.4 GB file

32K 72.5 GB · 128K 73.6 GB

How to run each

GPT OSS 20B

Ollama · Q4_K_M

$ollama run hf.co/unsloth/gpt-oss-20b-GGUF:Q4_K_M

All ways to run GPT OSS 20B →

Qwen3.6 35B A3B

Ollama · Q4_K_M

$ollama run hf.co/unsloth/Qwen3.6-35B-A3B-GGUF:Q4_K_M

All ways to run Qwen3.6 35B A3B →

Specifications

Specifications of GPT OSS 20B and Qwen3.6 35B A3B
Spec	GPT OSS 20B	Qwen3.6 35B A3B
Publisher	OpenAI	Alibaba
Parameters	20.9B	36.0B
Active parameters	4.2B per token	4.7B per token
Architecture	GptOssForCausalLM	Qwen3_5MoeForConditionalGeneration
Context	128K tokens	256K tokens
Modalities	Chat, Function-calling	Vision, Function-calling
License	Apache 2.0	Apache 2.0
Released	Aug 2025	Apr 2026

Frequently Asked Questions

Which is better, GPT OSS 20B or Qwen3.6 35B A3B?

Qwen3.6 35B A3B leads llmrun Score 106.9 to 96.2; both fit 24 GB at Q4_K_M; GPT OSS 20B is 1.3× faster on RTX 4090 (~190 vs ~151 tok/s). Choose GPT OSS 20B for fits a 12 GB GPU and 1.3× faster on RTX 4090; choose Qwen3.6 35B A3B for higher llmrun Score and stronger at science.

Which needs less VRAM, GPT OSS 20B or Qwen3.6 35B A3B?

At Q4_K_M, GPT OSS 20B requires 12.9 GB while Qwen3.6 35B A3B needs 22.0 GB, making GPT OSS 20B the easier model to run on your local setup.

Which is faster on RTX 4090?

Estimated decode speed on RTX 4090 is about 190 tok/s for GPT OSS 20B (Q4_K_M) and 151 tok/s for Qwen3.6 35B A3B (Q4_K_M), so GPT OSS 20B is faster. Estimates, ±20%.

Can I run GPT OSS 20B or Qwen3.6 35B A3B on a 16 GB GPU?

GPT OSS 20B fits at Q4_K_M; Qwen3.6 35B A3B fits at Q2_K.

Which has a longer context window, GPT OSS 20B or Qwen3.6 35B A3B?

GPT OSS 20B supports 131,072 tokens and Qwen3.6 35B A3B supports 262,144 tokens.