The MTLM1-200M is a compact but highly efficient language model built from scratch using a custom PyTorch implementation. It follows the modern Llama architecture principles, optimized for research and educational purposes.

This model demonstrates a significant performance leap compared to its predecessor (the 88M parameter version), validating the efficiency of well-executed layer stacking in this specific compute regime. It serves as a proof-of-concept for scalable training strategies on limited hardware.

⚙️ Training Methodology (The "Stacking" Strategy)

The training process employed a dynamic parameter efficient method to maximize resource usage:

Phase 1 (Base Learning): Training started with a smaller base model (~88M-100M parameters), allowing for rapid convergence on core linguistic patterns.
Phase 2 (Layer Stacking): Using a custom expansion technique, the layers were duplicated and stacked to effectively double the model depth.
Phase 3 (Refinement): The expanded 200M model continued training for a total of 1 Epochs over 3.5 Billion tokens, stabilizing the new weights and integrating the "M2 Blend" knowledge.

📚 Training Data (The "M1 Blend")

The dataset was curated to prioritize reasoning:

Synthetic & Textbook Quality: Subsets from Cosmopedia and FineWeb-Edu.
Web-Scale Foundation: Filtered portions of FineWeb.
Custom Knowledge Base: A collection of scraped Wikipedia articles, technical documents, and verified texts.

🛠️ Technical Specifications

Architecture: Llama-style (RMSNorm, SwiGLU, RoPE).
Attention: Flash Attention 2 (BF16 support).
Optimizer: AdamW + Cosine Scheduler.
Precision: Mixed Precision (BF16/AMP).

📊 Evaluation Results (Benchmarks)

Performance on standard zero-shot/few-sho(log prob ppl) benchmarks highlights the effectiveness of the stacking strategy compared to the previous 88M iteration:

Benchmark	Metric	Score (%)
Winogrande	Accuracy	50.00%
COPA	Accuracy	49.00%
BoolQ	Accuracy	44.25%
Winograd	Accuracy	43.27%
TruthfulQA (MC2)	Accuracy	41.42%
ARC Easy	Accuracy	38.64%
OpenBookQA	Accuracy	34.20%
HellaSwag	Accuracy	27.91%
Aqua-RAT	Accuracy	26.38%
TruthfulQA (MC1)	Accuracy	24.60%
ARC Challenge	Accuracy	23.55%
CommonSense QA	Accuracy	20.56%

🆚 Comparative Analysis

When compared to other models in the "Micro-LLM" class (<500M params) and even larger baselines, MTLM-200M demonstrates good performance in knowledge retrieval and academic reasoning tasks, outperforming the classic GPT-2 and the OPT-125M in key benchmarks.

Benchmark	Task	MTLM-200M (Ours)	OPT-125M	GPT-2 (124M)	TinyLlama 1.1B
OpenBookQA	Knowledge Retrieval	34.20%	~~30%	~32%%	~32.20 %
ARC-Easy	Science (Elementary)	39.64%	~35.0%	33.5%	49.62%
ARC-Challenge	Reasoning	23.55%	22.87%	21.8%	28.67%
TruthfulQA	Factuality (MC2)	41.42%	42.87%	~40.8%	39.15%
HellaSwag	Common Sense	27.91%	31.47%	29.4%	53.81%

🚀 Usage

python

from transformers import AutoModelForCausalLM, AutoTokenizer

model_id = "Madras1/MTLM1-200M"

tokenizer = AutoTokenizer.from_pretrained(model_id)
# trust_remote_code=True is required for custom modeling
model = AutoModelForCausalLM.from_pretrained(model_id, trust_remote_code=True)

inputs = tokenizer("Machine Learning is ", return_tensors="pt")
outputs = model.generate(**inputs, max_new_tokens=50)

print(tokenizer.decode(outputs[0], skip_special_tokens=True))

⚠️ Limitations Size: With 200M parameters, complex reasoning is limited compared to larger models.

Knowledge Cutoff: Dependent on the training dataset used.

Hallucinations: Like all LLMs, it may generate incorrect information.

Scope This is a base model intended for research, educational purposes, and edge-device experimentation. It has not undergone Reinforcement Learning from Human Feedback (RLHF) or SFT for safety alignment.