Seed 1.6 vs Llama 3.1 405B

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

Seed 1.6 is clearly ahead on the aggregate, 65 to 59. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Seed 1.6's sharpest advantage is in multimodal & grounded, where it averages 79.6 against 62.3. The single biggest benchmark swing on the page is MMMU-Pro, 80 to 60.

Seed 1.6 is the reasoning model in the pair, while Llama 3.1 405B is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Seed 1.6 gives you the larger context window at 256K, compared with 128K for Llama 3.1 405B.

Quick Verdict

Pick Seed 1.6 if you want the stronger benchmark profile. Llama 3.1 405B only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

Seed 1.6

Seed 1.6

62.3

Llama 3.1 405B

53.9

63
Terminal-Bench 2.0
53
67
BrowseComp
58
58
OSWorld-Verified
52

Coding

Seed 1.6

Seed 1.6

42.4

Llama 3.1 405B

40.6

64
HumanEval
62
46
SWE-bench Verified
46
38
LiveCodeBench
37
46
SWE-bench Pro
43

Multimodal & Grounded

Seed 1.6

Seed 1.6

79.6

Llama 3.1 405B

62.3

80
MMMU-Pro
60
79
OfficeQA Pro
65

Reasoning

Seed 1.6

Seed 1.6

74.5

Llama 3.1 405B

68.3

69
SimpleQA
68
69
MuSR
66
86
BBH
82
77
LongBench v2
68
78
MRCRv2
65

Knowledge

Seed 1.6

Seed 1.6

56.4

Llama 3.1 405B

53.2

73
MMLU
70
72
GPQA
70
70
SuperGPQA
68
68
OpenBookQA
66
75
MMLU-Pro
71
11
HLE
7
68
FrontierScience
65

Instruction Following

Seed 1.6

Seed 1.6

87

Llama 3.1 405B

86

87
IFEval
86

Multilingual

Seed 1.6

Seed 1.6

83.4

Llama 3.1 405B

80.1

88
MGSM
84
81
MMLU-ProX
78

Mathematics

Seed 1.6

Seed 1.6

75.9

Llama 3.1 405B

74.9

72
AIME 2023
70
74
AIME 2024
72
73
AIME 2025
71
68
HMMT Feb 2023
66
70
HMMT Feb 2024
68
69
HMMT Feb 2025
67
71
BRUMO 2025
69
82
MATH-500
82

Frequently Asked Questions

Which is better, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 is ahead overall, 65 to 59. The biggest single separator in this matchup is MMMU-Pro, where the scores are 80 and 60.

Which is better for knowledge tasks, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for knowledge tasks in this comparison, averaging 56.4 versus 53.2. Inside this category, MMLU-Pro is the benchmark that creates the most daylight between them.

Which is better for coding, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for coding in this comparison, averaging 42.4 versus 40.6. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for math in this comparison, averaging 75.9 versus 74.9. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for reasoning in this comparison, averaging 74.5 versus 68.3. Inside this category, MRCRv2 is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for agentic tasks in this comparison, averaging 62.3 versus 53.9. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for multimodal and grounded tasks in this comparison, averaging 79.6 versus 62.3. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for instruction following in this comparison, averaging 87 versus 86. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Seed 1.6 or Llama 3.1 405B?

Seed 1.6 has the edge for multilingual tasks in this comparison, averaging 83.4 versus 80.1. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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