Llama 3.1 405B vs LFM2.5-1.2B-Thinking

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

Llama 3.1 405B is clearly ahead on the aggregate, 59 to 33. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Llama 3.1 405B's sharpest advantage is in mathematics, where it averages 74.9 against 42.3. The single biggest benchmark swing on the page is HumanEval, 62 to 17.

LFM2.5-1.2B-Thinking 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. Llama 3.1 405B gives you the larger context window at 128K, compared with 32K for LFM2.5-1.2B-Thinking.

Quick Verdict

Pick Llama 3.1 405B if you want the stronger benchmark profile. LFM2.5-1.2B-Thinking only becomes the better choice if you want the stronger reasoning-first profile.

Agentic

Llama 3.1 405B

Llama 3.1 405B

53.9

LFM2.5-1.2B-Thinking

34.1

53
Terminal-Bench 2.0
34
58
BrowseComp
37
52
OSWorld-Verified
32

Coding

Llama 3.1 405B

Llama 3.1 405B

40.6

LFM2.5-1.2B-Thinking

8.2

62
HumanEval
17
46
SWE-bench Verified
10
37
LiveCodeBench
9
43
SWE-bench Pro
7

Multimodal & Grounded

Llama 3.1 405B

Llama 3.1 405B

62.3

LFM2.5-1.2B-Thinking

32.4

60
MMMU-Pro
27
65
OfficeQA Pro
39

Reasoning

Llama 3.1 405B

Llama 3.1 405B

68.3

LFM2.5-1.2B-Thinking

38.4

68
SimpleQA
29
66
MuSR
31
82
BBH
67
68
LongBench v2
39
65
MRCRv2
42

Knowledge

Llama 3.1 405B

Llama 3.1 405B

53.2

LFM2.5-1.2B-Thinking

27

70
MMLU
27
70
GPQA
26
68
SuperGPQA
24
66
OpenBookQA
22
71
MMLU-Pro
51
7
HLE
2
65
FrontierScience
31

Instruction Following

Llama 3.1 405B

Llama 3.1 405B

86

LFM2.5-1.2B-Thinking

72

86
IFEval
72

Multilingual

Llama 3.1 405B

Llama 3.1 405B

80.1

LFM2.5-1.2B-Thinking

60.7

84
MGSM
62
78
MMLU-ProX
60

Mathematics

Llama 3.1 405B

Llama 3.1 405B

74.9

LFM2.5-1.2B-Thinking

42.3

70
AIME 2023
28
72
AIME 2024
30
71
AIME 2025
29
66
HMMT Feb 2023
24
68
HMMT Feb 2024
26
67
HMMT Feb 2025
25
69
BRUMO 2025
27
82
MATH-500
61

Frequently Asked Questions

Which is better, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B is ahead overall, 59 to 33. The biggest single separator in this matchup is HumanEval, where the scores are 62 and 17.

Which is better for knowledge tasks, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for knowledge tasks in this comparison, averaging 53.2 versus 27. Inside this category, GPQA is the benchmark that creates the most daylight between them.

Which is better for coding, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for coding in this comparison, averaging 40.6 versus 8.2. Inside this category, HumanEval is the benchmark that creates the most daylight between them.

Which is better for math, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for math in this comparison, averaging 74.9 versus 42.3. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for reasoning in this comparison, averaging 68.3 versus 38.4. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for agentic tasks in this comparison, averaging 53.9 versus 34.1. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for multimodal and grounded tasks in this comparison, averaging 62.3 versus 32.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for instruction following in this comparison, averaging 86 versus 72. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, Llama 3.1 405B or LFM2.5-1.2B-Thinking?

Llama 3.1 405B has the edge for multilingual tasks in this comparison, averaging 80.1 versus 60.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

Weekly LLM Benchmark Digest

Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.

Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.