DeepSeek R1: The Open-Source Reasoning Model That Rivals OpenAI o1

What is DeepSeek R1?

DeepSeek-R1 is a first-generation reasoning model released in January 2025. It demonstrates that LLM reasoning abilities can be incentivized through pure reinforcement learning (RL), without requiring human-labeled reasoning trajectories.

Key Achievements

• AIME 2024: 79.8% pass@1 (American Invitational Mathematics Examination)
• MATH-500: 97.3% pass@1
• Codeforces: 2,029 Elo rating
• Performance comparable to OpenAI o1 across math, code, and reasoning tasks

Unique Architecture

DeepSeek R1 uses a Mixture of Experts (MoE) architecture with:

• 671 billion total parameters
• Only 37 billion activated per forward pass
• Built on DeepSeek-V3-Base foundation

This design makes R1 more resource-efficient than similarly large models, ensuring scalability without proportional increases in computational cost.

Training Innovations

DeepSeek R1 was trained using a novel approach:

1. Pure RL Training: DeepSeek-R1-Zero was trained via large-scale reinforcement learning without supervised fine-tuning
2. Emergent Capabilities: The model developed self-verification, reflection, and long Chain-of-Thought reasoning naturally
3. Cold-Start Data: Added to address issues like repetition and language mixing
4. Two-Stage Pipeline: RL stages for reasoning patterns + SFT stages for capabilities

Open Source & Commercial Use

Unlike many frontier models, DeepSeek R1 is fully open source:

• MIT License for code and weights
• Commercial use allowed
• Modifications and derivative works permitted
• Distillation for training other LLMs supported
• Available distilled versions: 1.5B, 7B, 8B, 14B, 32B, 70B

Using DeepSeek R1 with LemonData

Access DeepSeek R1 through LemonData's unified API at competitive rates:

from openai import OpenAI

client = OpenAI(
    api_key="your-lemondata-key",
    base_url="https://api.lemondata.cc/v1"
)

response = client.chat.completions.create(
    model="deepseek-r1",
    messages=[{
        "role": "user",
        "content": "Solve: What is the sum of all primes less than 100?"
    }]
)
print(response.choices[0].message.content)

When to Use DeepSeek R1

• Mathematical reasoning: Complex proofs, competition math
• Algorithmic problems: Dynamic programming, graph algorithms
• Code generation: When correctness matters more than speed
• Research: When you need transparent, open-source reasoning