Hands-on: Kimi K3.1 Pro Runs 2-3x Faster, Costs $0.55 in 5 Minutes
Blogger @cedricchee put Moonshot's new model Kimi K3.1 Pro to the test, concluding that it is 2-3x faster than K3, the previously criticized "overthinking" issue has been fixed, and overall it is a well-balanced model — open-source models are now close to frontier level on 3D generation and spatial reasoning tasks.
Confirmed
- The test task was a voxel garden (3D design and spatial reasoning), run using Kimi Code as the harness.
- Speed is 2-3x faster than K3.
- Cost breakdown (added later by the author): the high reasoning tier took 5 minutes, totaling roughly 1.06 million tokens (20k output, 5k reasoning), at a cost of $0.553; the max tier took 11 minutes, totaling roughly 1.67 million tokens, at a cost of $0.95.
- The author compared several frontier models on the same task, including Opus 5.5, GPT-6.1 Sol, Sonnet 5.5, DeepSeek V4.1-Flash, and Astra.
- The author says Kimi K3.1 Pro is about 5x cheaper than Astra.
Why it matters
- The hands-on test provides concrete token usage and cost figures, offering a direct benchmark for assessing the cost-effectiveness of open-source models on Agentic/3D generation tasks.
- If the "overthinking" issue is truly fixed and speed has doubled, the gap between open-source and closed-source frontier models on practical tasks narrows further — valuable reference for cost-conscious developers.
2026-10-24 ~ 2026-10-24 · 5 related posts
- Episode 1: Kimi K3.1 leaks pile up: Pro version rumored with open weights by Nov 4(2026-10-22, 18 posts)
- Episode 2: Moonshot teases Kimi K3.1 after strong Arena showing(2026-10-23, 4 posts)
- Episode 3: KOL Predicts Kimi K3.1 Benchmarks Before Testing, Suspects Benchmark Gaming(2026-10-23, 2 posts)
- Episode 4: Kimi K3.1 Pro Rolls Out: 3T-Parameter Flagship with 1M Context(2026-10-24, 12 posts)
- Episode 5: Kimi K3.1 Nails Pelican-on-Bicycle Test, Benchmark Declared Saturated(2026-10-24, 3 posts)
- Episode 6: Moonshot Releases Kimi K3.1 Pro, a 3T-Parameter Open-Weight Model Rivaling GPT-6 and Claude(2026-10-24, 50 posts)
- Episode 7: Nathan Lambert Calls Kimi K3.1 Pro the Strongest Open-Weight Model(2026-10-24, 2 posts)
- Episode 8: Kimi K3.1 Pro hits No.8 on WebDev Arena at ~30% of Opus 5's cost(2026-10-24, 7 posts)
- Episode 9: Moonshot's Kimi K3.1 Pro Hits #4 on Artificial Analysis Index, Closing the Open-Weights Gap(2026-10-24, 19 posts)
- Episode 10: Kimi K3.1 Pro hands-on: strong visuals, mixed general performance(2026-10-24, 2 posts)
- Episode 11: Hands-on: Kimi K3.1 Pro Runs 2-3x Faster, Costs $0.55 in 5 Minutes(2026-10-24, 5 posts)
Primary sources
- Kimi K3.1 Pro tested: 2-3x faster at $0.55 per task, open models close on frontier 3D — cedric_chee · 2026-10-24
- [source] Kimi K3.1 Pro cost breakdown: high mode $0.55/5min, max mode $0.95/11min — cedric_chee · 2026-10-24
- Kimi K3.1 Pro hands-on: 2-3x faster, 5x cheaper than Astra, fixes overthinking — cedric_chee · 2026-10-24
2 near-duplicate retellings: cedric_chee · cedric_chee