Text / LLM / Model
LLM360 K2-65B (K2 Diamond)
- Organisation
- LLM360 (MBZUAI / Petuum)
- Family
- LLM360 K2 · version 65B
- Released
- 2024-04-17 (HF createdAt of IFM/K2 (https://huggingface.co/api/models/IFM/K2); paper arXiv v1 2025-01-13)
- Checkpoints
- IFM/K2, IFM/K2-Chat
- Weights
- Open · apache-2.0
- Links
- PaperModel cardCode
Training data disclosure: Partial list
Level determined for 20% of benchmark cells.
- TestTest data seen2
- SeenSeen, split unclear0
- TrainTraining data seen0
- Related data seen1
- NoNot seen0
- ?Unknown12
“K2 is fully transparent, meaning we've open-sourced all artifacts, including code, data, model checkpoints, intermediate results, and more.”
“• Data: The exact sequence of training data, segmented into chunks corresponding to each checkpoint.”
“Safety & Alignment Data | 99,976,621”
Training corpora
-
K2Datasets (K2-65B / K2 Diamond pre-training data)
· 20 sources (complete list) · pre-training
· homepage
Evidence that LLM360 K2-65B (K2 Diamond) uses it
“K2 was trained on 1.4T tokens across two stages. The data sources and data mix for each stage are listed below.”
huggingface.co · dataset card · retrieved 2026-10-15 Contents of this corpus
-
dm-math (not yet matched to a dataset) · split: unknown
Evidence
“[dm-math](https://github.com/google-deepmind/mathematics_dataset) | 4.33B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
pubmed-abstracts (from the Pile) (not yet matched to a dataset) · split: unknown
Evidence
“pubmed-abstracts (from the Pile) | 4.77B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
uspto (from the Pile) (not yet matched to a dataset) · split: unknown
Evidence
“uspto (from the Pile) | 4.77B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
pubmed-central (from the Pile) (not yet matched to a dataset) · split: unknown
Also used in stage 2.
Evidence
“pubmed-central (from the Pile) | 26B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
redpajama.arxiv (not yet matched to a dataset) · split: unknown
Also used in stage 2 (2B tokens).
Evidence
“[redpajama.arxiv](https://huggingface.co/datasets/cerebras/SlimPajama-627B) | 27.3B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
starcoder.spm (broad web data: may contain benchmark test sets) · split: unknown
Evidence
“[starcoder.spm](https://huggingface.co/datasets/bigcode/starcoderdata) | 67.6B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
starcoder.fim (broad web data: may contain benchmark test sets) · split: unknown
Evidence
“[starcoder.fim](https://huggingface.co/datasets/bigcode/starcoderdata) | 67.6B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
redpajama.stackexchange (not yet matched to a dataset) · split: unknown
Evidence
“[redpajama.stackexchange](https://huggingface.co/datasets/cerebras/SlimPajama-627B) | 61.1B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
starcoder (broad web data: may contain benchmark test sets) · split: unknown
Evidence
“[starcoder](https://huggingface.co/datasets/bigcode/starcoderdata) | 132.6B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
pile-of-law (not yet matched to a dataset) · split: unknown
Also used in stage 2.
Evidence
“[pile-of-law](https://huggingface.co/datasets/pile-of-law/pile-of-law) | 76.7B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
redpajama.book (not yet matched to a dataset) · split: unknown
Also used in stage 2.
Evidence
“[redpajama.book](https://huggingface.co/datasets/cerebras/SlimPajama-627B) | 80.6B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
s2orc (not yet matched to a dataset) · split: unknown
Also used in stage 2.
Evidence
“[s2orc](https://allenai.org/data/s2orc) | 107.9B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
redpajama.wikipedia (not yet matched to a dataset) · split: unknown
Also used in stage 2.
Evidence
“[redpajama.wikipedia](https://huggingface.co/datasets/cerebras/SlimPajama-627B) | 22.1B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
refinedweb (broad web data: may contain benchmark test sets) · split: unknown
Evidence
“[refinedweb](https://huggingface.co/datasets/tiiuae/falcon-refinedweb) | 612.3B”
huggingface.co · dataset card · Dataset Description: Stage 1 table · retrieved 2026-10-15 -
open-web-math (broad web data: may contain benchmark test sets) · split: unknown
Stage 2 only; math web pages filtered from Common Crawl.
Evidence
“[open-web-math](https://huggingface.co/datasets/EleutherAI/proof-pile-2) | 14.6B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15 -
simple-wiki (not yet matched to a dataset) · split: unknown
Stage 2 only.
Evidence
“[simple-wiki](https://huggingface.co/datasets/allenai/dolma) | 4.3B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15 -
algebraic-stack (broad web data: may contain benchmark test sets) · split: unknown
Stage 2 only; math-related code from GitHub-derived sources (Proof-Pile-2).
Evidence
“[algebraic-stack](https://huggingface.co/datasets/EleutherAI/proof-pile-2) | 10.9B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15 -
books (not yet matched to a dataset) · split: unknown
Stage 2 only; source of this books set is not stated.
Evidence
“books | 5.8B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15 -
pes20 (not yet matched to a dataset) · split: unknown
Stage 2 only (peS2o).
Evidence
“[pes20](https://huggingface.co/datasets/allenai/peS2o) | 1.2B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15 -
python (not yet matched to a dataset) · split: unknown
Stage 2 only; provenance of this Python code is not stated.
Evidence
“python | 20.5B”
huggingface.co · dataset card · Dataset Description: Stage 2 table · retrieved 2026-10-15
-
dm-math (not yet matched to a dataset) · split: unknown
-
The Pile
· 22 sources (complete list) · pre-training
· homepage
Evidence that LLM360 K2-65B (K2 Diamond) uses it
“pubmed-abstracts (from the Pile) | 4.77B”
huggingface.co · dataset card · Stage 1 table · retrieved 2026-10-15 “uspto (from the Pile) | 4.77B”
huggingface.co · dataset card · Stage 1 table · retrieved 2026-10-15 “pubmed-central (from the Pile) | 26B”
huggingface.co · dataset card · Stage 1 table · retrieved 2026-10-15 Contents of this corpus
-
Pile-CC (broad web data: may contain benchmark test sets) · split: unknown
Filtered subset of Common Crawl.
-
PubMed Central (not yet matched to a dataset) · split: unknown
Evidence
“PubMed Central”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Books3 (not yet matched to a dataset) · split: unknown
Marked with a dagger in Table 1 (used with minimal preprocessing from prior work).
Evidence
“Books3”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
OpenWebText2 (broad web data: may contain benchmark test sets) · split: unknown
Web scrape of Reddit-upvoted outgoing links, content up until 2020.
-
ArXiv (not yet matched to a dataset) · split: unknown
Evidence
“ArXiv”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Github (broad web data: may contain benchmark test sets) · split: unknown
GitHub code dump.
-
FreeLaw (not yet matched to a dataset) · split: unknown
Evidence
“FreeLaw”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Stack Exchange (not yet matched to a dataset) · split: unknown
Evidence
“Stack Exchange”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
USPTO Backgrounds (not yet matched to a dataset) · split: unknown
Evidence
“USPTO Backgrounds”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
PubMed Abstracts (not yet matched to a dataset) · split: unknown
Evidence
“PubMed Abstracts”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Gutenberg (PG-19) (not yet matched to a dataset) · split: unknown
Evidence
“Gutenberg (PG-19)”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
OpenSubtitles (not yet matched to a dataset) · split: unknown
Evidence
“OpenSubtitles”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Wikipedia (en) (not yet matched to a dataset) · split: unknown
Evidence
“Wikipedia (en)”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
DM Mathematics (not yet matched to a dataset) · split: unknown
DeepMind Mathematics (Saxton et al., 2019); which of its splits are included is not stated in the quoted text.
-
Ubuntu IRC (not yet matched to a dataset) · split: unknown
Evidence
“Ubuntu IRC”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
BookCorpus2 (not yet matched to a dataset) · split: unknown
Evidence
“BookCorpus2”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
EuroParl (not yet matched to a dataset) · split: unknown
Evidence
“EuroParl”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
HackerNews (not yet matched to a dataset) · split: unknown
Evidence
“HackerNews”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
YoutubeSubtitles (not yet matched to a dataset) · split: unknown
Evidence
“YoutubeSubtitles”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
PhilPapers (not yet matched to a dataset) · split: unknown
Evidence
“PhilPapers”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
NIH ExPorter (not yet matched to a dataset) · split: unknown
Evidence
“NIH ExPorter”
arxiv.org · paper · Table 1 · retrieved 2026-10-15 -
Enron Emails (not yet matched to a dataset) · split: unknown
Evidence
“Enron Emails”
arxiv.org · paper · Table 1 · retrieved 2026-10-15
-
Pile-CC (broad web data: may contain benchmark test sets) · split: unknown
Other declared training data
-
Infinity-Instruct (not yet matched to a dataset) · split: unknown · fine-tuning
K2-Chat (10/31/24 update).
Evidence
“[Infinity-Instruct](https://huggingface.co/datasets/BAAI/Infinity-Instruct)”
huggingface.co · model card · intro, datasets list · retrieved 2026-10-15 -
JiuZhang3.0-Corpus-SFT (not yet matched to a dataset) · split: unknown · fine-tuning
K2-Chat (10/31/24 update).
Evidence
“[JiuZhang3.0-Corpus-SFT](https://huggingface.co/datasets/ToheartZhang/JiuZhang3.0-Corpus-SFT)”
huggingface.co · model card · intro, datasets list · retrieved 2026-10-15 -
glaive-function-calling-v2-sharegpt (not yet matched to a dataset) · split: unknown · fine-tuning
K2-Chat (10/31/24 update).
Evidence
“[glaive-function-calling-v2-sharegpt](https://huggingface.co/datasets/hiyouga/glaive-function-calling-v2-sharegpt)”
huggingface.co · model card · intro, datasets list · retrieved 2026-10-15 -
MathInstruct (not yet matched to a dataset) · split: unknown · fine-tuning
Composite of 13 math datasets; which benchmark splits it contains is not stated in K2 sources (see open_questions).
Evidence
“[MathInstruct](https://huggingface.co/datasets/TIGER-Lab/MathInstruct) | 66,639,699”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 “MathInstruct (Yue et al., 2023): A composite dataset combining 13 math-focused resources, six of which included newly created rationales.”
arxiv.org · paper · Section 5.1.2 · retrieved 2026-10-15 -
OpenHermes-2.5 (not yet matched to a dataset) · split: unknown · fine-tuning
Evidence
“[OpenHermes-2](https://huggingface.co/datasets/teknium/OpenHermes-2.5) |404,820,694”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 “OpenHermes-2.5 (Teknium, 2023): This dataset includes 1M samples, primarily derived from GPT-4-generated entries and filtered for quality.”
arxiv.org · paper · Section 5.1.2 · retrieved 2026-10-15 -
FLAN_3M (not yet matched to a dataset) · split: unknown · fine-tuning
FLAN task collection; which benchmark training splits are included is not stated.
Evidence
“[FLAN_3M](https://arxiv.org/abs/2109.01652) | 2,346,961,387”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 “FLAN (Wei et al.; Longpre et al., 2023): Developed by Google Research, FLAN contains 3M samples covering tasks such as translation, summarization, and question-answering.”
arxiv.org · paper · Section 5.1.2 · retrieved 2026-10-15 -
Standford Encyclopedia Philosophy (not yet matched to a dataset) · split: unknown · fine-tuning
Evidence
“[Standford Encyclopedia Philosophy](https://huggingface.co/datasets/AiresPucrs/stanford-encyclopedia-philosophy) | 786,928”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 -
TinyStories (not yet matched to a dataset) · split: unknown · fine-tuning
Evidence
“[TinyStories](https://huggingface.co/datasets/roneneldan/TinyStories) | 1,448,898”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 -
Safety & Alignment Data (not yet matched to a dataset) · split: unknown · fine-tuning
In-house annotated attack prompts (~1,200 seed + 50,000 LLM-assisted) plus open-source safety sets (AART, AnthropicHarmlessBase, AnthropicRedTeam, BBQ, ForbiddenQuestions, HarmfulQA, ParlAIDialogueSafety, ProsocialDialog, ToxicChat, ...), responses generated with GPT.
Evidence
“Safety & Alignment Data | 99,976,621”
huggingface.co · model card · K2-Chat-060124, Datasets and Mix · retrieved 2026-10-15 “Our safety SFT dataset comprises three main components. The first component is the direct attack prompts, aimed at enhancing the model's alignment with safety values.”
arxiv.org · paper · Section 6.1 · retrieved 2026-10-15 -
Do-Not-Answer (2,700 samples) (not yet matched to a dataset) · split: unknown · fine-tuning
Evidence
“To discourage harmful behavior, 2,700 samples from the Do-Not-Answer dataset (Wang et al., 2024) were combined with cultural alignment prompts.”
arxiv.org · paper · Section 5.1.2 · retrieved 2026-10-15 -
Self-synthesized math and reasoning examples (300K) (not yet matched to a dataset) · split: unknown · fine-tuning
Model-generated (OpenAI API) and algorithm-generated math traces; not stated to be released.
Evidence
“and 300K self-synthesized math and reasoning examples.”
arxiv.org · paper · Section 5.1 · retrieved 2026-10-15
Contamination analyses
Analyses that found benchmark test data in this model's training data, or in a corpus it uses.
-
HumanEval
· pre-training data · in The Pile
Riddell et al. (2024): 12.2% of HumanEval gold solutions have a perfect (surface- or semantic-level) match in the Pile's GitHub split; CONDA 2024 contamination report also lists openai_humaneval as found (>0%) in EleutherAI/pile. (WIMBD's exact-match input-field check reports 0.00% for openai-humaneval in the Pile, Table 16.)
Evidence
“Results in Fig. 1 show that 12.2% of the solutions in HumanEval have been seen by models trained on the P ILE”
arxiv.org third-party study· study · Section 4.1 · retrieved 2026-10-15 “We use the GitHub split of the training dataset, which has a raw size of 95.16 GiB.”
arxiv.org third-party study· study · Section 3.1 · retrieved 2026-10-15 “amazon_reviews_multi (Keung et al., 2020), mbpp, openai_humaneval (Chen et al., 2021), liar”
arxiv.org third-party study· study · Table 1 (row EleutherAI/pile) · retrieved 2026-10-15 -
MMLU (Measuring Massive Multitask Language Understanding)
· pre-training data · in The Pile
MMLU test questions are also substantially 'dirty' in Pile-train: DCLM-baseline (27.70%) has only 1.1x more dirty entries than Pile-train. Exact Pile-train rate is in Table 2 (not reliably extracted from the PDF text).
Evidence
“Compared with Pile-train, most benchmarks show a higher dirty rate on DCLM-baseline. For example, ARC-Challenge has 17× more and MMLU has 1.1× more dirty entries.”
arxiv.org third-party study· study · Section 4.2 · retrieved 2026-10-15
Benchmark cells
Classic LLM benchmarks
Test data seen MMLU (Measuring Massive Multitask Language Understanding) · a contamination analysis found test examples in the pre-training data (MMLU test questions are also substantially 'dirty' in Pile-train: DCLM-baseline (27.70%) has only 1.1x more dirty entries than Pile-train. Exact Pile-train rate is in Table 2 (not reliably extracted from the PDF text).) [third-party study] (via The Pile)
Evidence (4)
“pubmed-abstracts (from the Pile) | 4.77B”
“uspto (from the Pile) | 4.77B”
“pubmed-central (from the Pile) | 26B”
“Compared with Pile-train, most benchmarks show a higher dirty rate on DCLM-baseline. For example, ARC-Challenge has 17× more and MMLU has 1.1× more dirty entries.”
Unknown GSM8K (Grade School Math 8K) · training data not disclosed in enough detail
Unknown MATH (Mathematics Aptitude Test of Heuristics) · training data not disclosed in enough detail
Test data seen HumanEval · a contamination analysis found test examples in the pre-training data (Riddell et al. (2024): 12.2% of HumanEval gold solutions have a perfect (surface- or semantic-level) match in the Pile's GitHub split; CONDA 2024 contamination report also lists openai_humaneval as found (>0%) in EleutherAI/pile. (WIMBD's exact-match input-field check reports 0.00% for openai-humaneval in the Pile, Table 16.)) [third-party study] (via The Pile)
Evidence (6)
“pubmed-abstracts (from the Pile) | 4.77B”
“uspto (from the Pile) | 4.77B”
“pubmed-central (from the Pile) | 26B”
“Results in Fig. 1 show that 12.2% of the solutions in HumanEval have been seen by models trained on the P ILE”
“We use the GitHub split of the training dataset, which has a raw size of 95.16 GiB.”
“amazon_reviews_multi (Keung et al., 2020), mbpp, openai_humaneval (Chen et al., 2021), liar”
Unknown ARC-Challenge (AI2 Reasoning Challenge, Challenge Set) · training data not disclosed in enough detail
Unknown HellaSwag · training data not disclosed in enough detail
Unknown TruthfulQA · training data not disclosed in enough detail
Unknown WinoGrande · training data not disclosed in enough detail
Recent LLM benchmarks
Unknown GPQA Diamond · training data not disclosed in enough detail
MMLU-Pro · a contamination analysis found test examples of the related dataset MMLU (Measuring Massive Multitask Language Understanding) (MMLU test questions are also substantially 'dirty' in Pile-train: DCLM-baseline (27.70%) has only 1.1x more dirty entries than Pile-train. Exact Pile-train rate is in Table 2 (not reliably extracted from the PDF text).) [third-party study] (via The Pile)
Evidence (6)
“pubmed-abstracts (from the Pile) | 4.77B”
“uspto (from the Pile) | 4.77B”
“pubmed-central (from the Pile) | 26B”
“Compared with Pile-train, most benchmarks show a higher dirty rate on DCLM-baseline. For example, ARC-Challenge has 17× more and MMLU has 1.1× more dirty entries.”
“**Original MMLU Questions:** Part of the dataset comes from the original MMLU dataset. We remove the trivial and ambiguous questions.”
“Additionally, MMLU-Pro eliminates the trivial and noisy questions in MMLU.”
Unknown LiveCodeBench (code generation, release_v6) · training data not disclosed in enough detail
Unknown SWE-bench Verified · training data not disclosed in enough detail
Unknown AIME 2024 · training data not disclosed in enough detail
Unknown AIME 2025 · training data not disclosed in enough detail
Unknown MATH-500 · training data not disclosed in enough detail
Notes
Pre-training data fully released (k2-data). Fine-tuning data recorded for two K2-Chat releases: K2-Chat-060124 (MathInstruct, OpenHermes-2.5, FLAN_3M, philosophy encyclopedia, TinyStories, safety data) and the 10/31/24 update (adds Infinity-Instruct, JiuZhang3.0-Corpus-SFT, glaive function calling). Disclosure partial_list because the in-house safety prompts and self-synthesized math data are described but not shown to be released.
Sources
- LLM360 K2: Building a 65B 360-Open-Source Large Language Model from Scratch (arXiv 2501.07124v3) · paper · retrieved 2026-10-15
- IFM/K2 model card · model card · retrieved 2026-10-15
- IFM/K2-Chat model card · model card · retrieved 2026-10-15
- IFM/K2Datasets dataset card · dataset card · retrieved 2026-10-15