Trinity-Large-Base
Introduction
Trinity-Large-Base is a pretrained foundation model from Arcee AI's Trinity Large training run. It is a 398B-parameter sparse Mixture-of-Experts (MoE) model with approximately 13B active parameters per token. The checkpoint was captured after 17 trillion tokens of pretraining, including mid-training learning-rate anneals and context extension, but prior to any instruction tuning or reinforcement learning.
This checkpoint represents the completed pretraining phase and serves as a foundation for research and downstream fine-tuning.
More details on the training of Trinity Large are available in the technical report.
Model Variants
The Trinity Large family consists of three checkpoints from the same training run:
- Trinity-Large-Base (this release): Full 17T-token pretrained foundation model with mid-training anneals
- Trinity-Large-Thinking: Reasoning-optimized, agentic post-training with extended chain-of-thought
- Trinity-Large-TrueBase: 10T-token pre-anneal checkpoint with no instruction data
- Trinity-Large-Preview: Lightly post-trained, chat-ready model undergoing active RL
Architecture
Trinity-Large-Base uses a sparse MoE configuration designed to maximize efficiency while maintaining large-scale capacity.
| Hyperparameter | Value |
|---|---|
| Total parameters | ~398B |
| Active parameters per token | ~13B |
| Experts | 256 |
| Active experts | 4 |
| Routing strategy | 4-of-256 (1.56% sparsity) |
| Dense layers | 6 |
| Pretraining context length | 8,192 |
| Context length after extention | 512k |
| Architecture | Sparse MoE (AfmoeForCausalLM) |
Benchmark Results
| Benchmark | N-shot | Metric | Score | Stderr |
|---|---|---|---|---|
| mbpp_plus | 3 | pass_at_1,none | 0.8862 | ±0.0164 |
| minerva_math500 | 4 | math_verify,none | 0.6520 | ±0.0213 |
| hellaswag_5shot | 5 | acc_norm,none | 0.9011 | ±0.0030 |
| winogrande_5shot | 5 | acc,none | 0.8082 | ±0.0111 |
| mmlu_5shot | 5 | acc,none | 0.8258 | ±0.0031 |
| mmlu_generative_5shot | 5 | exact_match,get_response | 0.8260 | ±0.0031 |
| mmlu_pro | 5 | exact_match,custom-extract | 0.6602 | ±0.0042 |
| triviaqa_5shot | 5 | exact_match,remove_whitespace | 0.8330 | ±0.0028 |
| arc_challenge_0shot | 0 | acc_norm,none | 0.6544 | ±0.0139 |
| bbh_fewshot | 3 | exact_match,remove_whitespace | 0.6570 | ±0.0051 |
| gpqa_diamond_5shot | 5 | acc_norm,none | 0.4394 | ±0.0354 |
| gsm8k_cot | 8 | exact_match,flexible-extract | 0.9136 | ±0.0077 |
Training Configuration
Pretraining
- Training tokens: 17 trillion
- Checkpoint type: Post-anneal (foundation)
- Instruction data: None
- RLHF or post-training: None
This checkpoint represents the final pretrained state after completion of the pretraining phase, including mid-training learning-rate anneals, but before instruction tuning or reinforcement learning.
Optimizers
Optimizer learning rates during WSD stable phase:
- Adam learning rate: 2e-4
- Muon learning rate: 8e-4
Muon was used to support larger critical batch sizes in a highly sparse MoE regime.
Infrastructure
- Hardware: 2,048 NVIDIA B300 GPUs
- Parallelism: HSDP + Expert Parallelism
- Compute partner: Prime Intellect
- Data partner: Datology
Intended Use
- Studying emergent behavior from large-scale pretraining
- Sparse MoE routing and load-balancing research
- Interpretability, probing, and ablation studies
- Domain-specific fine-tuning from a pretrained foundation
- Academic and industrial foundation model research
Comparison with TrueBase
Trinity-Large-Base includes an additional 7 trillion training tokens compared to Trinity-Large-TrueBase, along with mid-training learning-rate anneals. These anneals stabilize training dynamics and typically improve downstream fine-tuning performance compared to the pre-anneal checkpoint. Researchers studying raw pretraining dynamics may prefer TrueBase, while those seeking a foundation for fine-tuning may prefer this checkpoint.
Known Limitations
- Not aligned for safety, helpfulness, or conversational tone
- Requires substantial compute and expertise to fine-tune
- May exhibit raw or unstable behaviors typical of unaligned models
- No extended-context tuning beyond the 8K pretraining window
License
Trinity-Large-Base is released under the OpenMDW License, version 1.1 (OpenMDW-1.1).