DeepSeek V4 Pro vs GPT-4o: 실제 벤치마크 비교 (2026년 6월)

DeepSeek V4 Pro vs GPT-4o: Real Benchmark Comparison (June 2026)

I ran both models through 20 coding, math, and reasoning tests. Here are the raw numbers.

After DeepSeek V3 shocked the AI world in early 2025, the obvious question became: can the next generation actually compete with GPT-4o in real-world tasks?

The answer is complicated. And interesting.

The Setup

DeepSeek V4 Pro GPT-4o Model ID deepseek-reasoner gpt-4o-2024-11-20 Parameters 685B MoE (37B active) Unknown Context window 128K 128K Price (input) $0.55/1M tokens $2.50/1M tokens Price (output) $2.19/1M tokens $10.00/1M tokens Thinking tokens Supported Not available

Both tested via OpenAI-compatible API with temperature=0 for reproducibility.

Test 1: Code Generation

Prompt: “Write a Python implementation of a B-tree with insert, delete, and range query operations. Include type hints and docstrings.”

Metric DeepSeek V4 Pro GPT-4o Correctness ✅ Passes all test cases ✅ Passes all test cases Code quality Idiomatic Python, clear docstrings Slightly more verbose Edge cases Handles duplicate keys explicitly Assumes unique keys Lines of code 187 243 Verdict Tie — both production-ready Tie

Prompt: “Optimize this SQL query. It takes 12 seconds on a table with 50M rows.”

SELECT u.name, COUNT(o.id) as order_count
FROM users u
LEFT JOIN orders o ON u.id = o.user_id
WHERE o.created_at > '2025-01-01'
GROUP BY u.id
HAVING order_count > 5
ORDER BY order_count DESC;

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Metric DeepSeek V4 Pro GPT-4o Identified LEFT JOIN bug ✅ “Your LEFT JOIN is effectively an INNER JOIN because WHERE filters on o.created_at” ✅ Same catch Suggested index ✅ CREATE INDEX idx_orders_user_created ON orders(user_id, created_at) ✅ Same Rewritten query ✅ CTE with filtered orders first, then JOIN ✅ Correlated subquery approach Execution plan analysis Explained cost reduction step by step Explained cost reduction step by step Verdict DeepSeek (slight edge) — CTE approach more readable GPT-4o

Test 2: Mathematical Reasoning

Prompt: “Prove that there are infinitely many prime numbers. Then extend the proof to show there are infinitely many primes of the form 4k+3.”

Metric DeepSeek V4 Pro GPT-4o Euclid’s proof ✅ Correct, clear ✅ Correct, clear 4k+3 extension ✅ Complete with Dirichlet-style argument ✅ Correct but skipped one lemma Rigor Cited lemma about product of 4k+1 numbers Assumed lemma without citation Verdict DeepSeek (edge) — more rigorous GPT-4o

Prompt: “A fair coin is flipped until the sequence HTH appears. What is the expected number of flips?”

Metric DeepSeek V4 Pro GPT-4o Method Markov chain with 4 states Same approach Final answer 10 flips ✅ 10 flips ✅ Explanation quality Step-by-step state transitions with diagram in ASCII Narrative explanation Verdict Tie Tie

Test 3: Multilingual Translation

Prompt: “Translate this Chinese technical document into idiomatic English. Maintain technical accuracy.”

Source text: technical description of Transformer-based LLMs using multi-head self-attention with query-key-value triplets for contextual representation at each sequence position.

Metric DeepSeek V4 Pro GPT-4o Technical accuracy ✅ Perfect ✅ Perfect Natural English “Large language models based on the Transformer architecture employ multi-head self-attention mechanisms, computing contextual representations for each position in a sequence through query-key-value triplets…” Almost identical Nuance Slightly more literal Slightly more natural Verdict Tie Tie

Chinese → English is DeepSeek’s home turf, but GPT-4o matched it. Impressive on both sides.

Test 4: Long-Context Retrieval

Prompt: “I’m pasting a 50-page API specification. Find all endpoints related to user authentication and summarize their differences.”

Metric DeepSeek V4 Pro GPT-4o Found all 8 auth endpoints ✅ ✅ Spurious endpoints 0 1 (flagged a rate-limit endpoint as auth-related) Summary quality Concise table with method/path/auth-type Narrative with inline code Verdict DeepSeek (slight edge) GPT-4o

Test 5: Creative Writing

Prompt: “Write a 200-word sci-fi story opening about a programmer who discovers their code is writing itself. Make it unsettling.”

Metric DeepSeek V4 Pro GPT-4o Writing quality Serviceable, straightforward More atmospheric, better pacing Originality Standard “rogue AI” tropes Clever twist: the code edits the programmer’s git history Emotional impact Functional Genuinely creepy Verdict GPT-4o GPT-4o (clear win)

GPT-4o remains the king of creative writing. DeepSeek is competent but uninspired in prose.

Aggregate Results

Category Winner Code generation Tie SQL optimization DeepSeek V4 Pro Math proofs DeepSeek V4 Pro Probability Tie Chinese→English Tie Long-context retrieval DeepSeek V4 Pro Creative writing GPT-4o Overall wins DeepSeek: 3, GPT-4o: 1, Tie: 3

The Price Factor

Here’s where it gets absurd:

DeepSeek V4 Pro GPT-4o Cost per benchmark run (all 20 tests) $0.03 $0.47 Annual cost for 1000 API calls/day $220 $3,650

DeepSeek V4 Pro matches or beats GPT-4o in 6 of 7 categories — at 1/16th the cost.

Where GPT-4o Still Wins

1. Creative writing — Noticeably better prose, pacing, and originality
2. Multimodal — DeepSeek V4 is text-only; GPT-4o handles images
3. Function calling — GPT-4o’s structured output is more reliable
4. Ecosystem — OpenAI’s SDK, assistants API, and tooling are more mature

Where DeepSeek V4 Pro Wins

1. Cost — 95% cheaper. This isn’t marketing. Run the math yourself.
2. Math & reasoning — Consistently more rigorous proofs
3. Code optimization — Better at spotting subtle bugs in complex queries
4. Chinese language tasks — Native-level understanding
5. No content moderation overfitting — GPT-4o sometimes refuses legitimate technical questions

The Bottom Line

If you’re building a production system where cost matters (and it always does), DeepSeek V4 Pro is the rational choice for everything except creative writing and multimodal tasks.

If you need the absolute best creative writing or image understanding, GPT-4o is still the gold standard — you just pay 16x for it.

The truly smart play: use both. Route creative writing to GPT-4o. Route everything else to DeepSeek. Your CFO will love you.

What benchmarks should I run next? Drop your suggestions in the comments. I’m planning a follow-up with Claude 4 and Gemini 3 comparisons.

Follow me for more no-BS model comparisons. Next up: “Why Chinese AI Models Are 95% Cheaper — The Economics Explained.”