Qwen 2 72B VS ChatGPT 4o

2025-12-20

The landscape of Large Language Models (LLMs) is evolving rapidly. Today, we delve into a comprehensive comparison between two industry titans: ChatGPT 4o (Omni), the flagship multimodal model from OpenAI, and Qwen 2 72B Instruct, the sophisticated open-source powerhouse from Alibaba Cloud. This analysis covers technical specifications, benchmark performance, and real-world practical testing.

Technical Specifications & Hardware Logic

Specification ChatGPT 4o Qwen 2 72B Instruct
Context Window 128K Tokens 128K Tokens
Knowledge Cutoff October 2023 2023 (Month Unspecified)
Parameters > 175B (Estimated) 72B
Release Date May 13, 2024 June 7, 2024

While Qwen 2 matches the 128K context window—essential for processing long documents—ChatGPT 4o maintains an advantage in sheer scale. However, Qwen 2's architecture is highly optimized for efficiency, making it a formidable rival in the open-source community.

Performance Benchmarks

The following data represents a synthesis of official release notes and independent open benchmarks, as originally discussed in Benchmarks and specs.

Benchmark Category ChatGPT 4o Qwen 2 72B
MMLU (Undergrad Knowledge) 88.7 82.3
GPQA (Graduate Reasoning) 53.6 42.4
Human Eval (Coding) 90.2 86.0
GSM8K (School Math) 90.5 91.1

Real-World Practical Tests

💡 Test 1: Nuance and Sarcastic Creativity

Prompt: Provide 10 sarcastic jokes about coding struggles.

Results:

  • ChatGPT 4o: Excellent execution. It understood the structural pattern of the "dad/son" dynamic and delivered high-quality developer humor.
  • Qwen 2: Surprising depth. While slightly more "avant-garde," the jokes were technically accurate and humorous (e.g., debugging Python logic).

🧩 Test 2: Logical Reasoning (The Sock Problem)

The Challenge: Calculating the minimum socks needed to guarantee a pair from a specific set in the dark.

"A man has 53 socks: 21 blue, 15 black, 17 red. How many to guarantee 1 pair of black?"

Both models correctly identified the worst-case scenario (picking all non-target colors first):

Calculation: 21 (Blue) + 17 (Red) + 2 (Black) = 40 Socks

Verdict: Both scored 100%. GPT 4o was more verbose, while Qwen 2 was more direct.

👁️ Test 3: Vision and Image Reasoning

In "trick question" scenarios involving image analysis, ChatGPT 4o remains the leader. It possesses native multimodal capabilities that allow it to understand physical states (like a cup being upside down) better than most open-source competitors. Note: Qwen 2 72B Instruct is primarily a text model; vision tasks are usually handled by its sister model, Qwen-VL.

Cost Efficiency & API Pricing

For developers, the price-to-performance ratio is often the deciding factor. Based on AICC API rates:

Model Input (per 1k tokens) Output (per 1k tokens)
Qwen 2 $0.00117 $0.00117
ChatGPT 4o $0.0065 $0.0195

Analysis: ChatGPT 4o is significantly more expensive, particularly for output tokens. Qwen 2 offers a massive cost saving for high-volume text generation.

Summary of Comparison

ChatGPT 4o remains the gold standard for complex reasoning, native multimodal tasks (vision/voice), and speed. It is 1.5x faster and slightly more "intelligent" in graduate-level logic.

Qwen 2 72B is the premier open-source choice. It rivals GPT-4 class models in coding and mathematics while being significantly more affordable. It is ideal for researchers and enterprises looking for high-performance text processing without the "OpenAI tax."

Frequently Asked Questions (FAQ)

1. Which model is better for coding?
ChatGPT 4o has a slight edge in complex system design, but Qwen 2 is remarkably close in HumanEval scores. For standard script generation, both are excellent.

2. Can Qwen 2 process images?
The standard Qwen 2 72B Instruct is a text-based model. For vision tasks, OpenAI's GPT-4o is natively multimodal and performs better out-of-the-box.

3. Why is there a price difference?
ChatGPT 4o is a proprietary "Model-as-a-Service," whereas Qwen 2 is an open-source model. Using Qwen 2 via an API is cheaper because the underlying infrastructure costs for 72B models are lower than for the massive GPT-4o architecture.

4. Is the context window the same for both?
Yes, both models support up to 128,000 tokens, making them suitable for analyzing long-form documents or large code repositories.