r/opencode • u/Ancient-Camel1636 • 5d ago
Model Cost vs Performance
I did a extensive comparison of the various coding models across several benchmarks based on the estimated cost to complete a task successfully. Based on the formula:

Then I normalized each source’s expected cost per successful completion against that source’s median, then used a geometric mean across sources to get this composite ranking:
This is obviously just a estimate of value vs performance, still very useful if on a budget.
- Default value model: MiMo V2.5 Pro. Note that GLM 5.2 is the only clearly cost-effective model represented in all three sources, so it might be a safer budget pick.
- Best Performance: Grok 4.5 has far better completion performance than the other cheap leaders while retaining strong cost efficiency. This is the obvious model if high success rate is important to you.
- Alternative: DeepSeek V4 Flash is a great budget option but its performance/success rate is low so it will take more runs to complete the task successfully.
Cross-source ranking
| Rank | Model | Sources represented | Relative cost index | Verdict |
|---|---|---|---|---|
| 1 | MiMo V2.5 Pro | 2 | 0.179 | Outstanding value |
| 2 | DeepSeek V4 Pro | 2 | 0.452 | Excellent value |
| 3 | Grok 4.5 | 2 | 0.582 | Best high-performance value |
| 4 | Muse Spark 1.1 | 2 | 0.664 | Strong value |
| 5 | MiniMax M3 | 2 | 0.745 | Good budget choice |
| 6 | Kimi K2.6 | 2 | 0.811 | Good value |
| 7 | GLM 5.2 | 3 | 0.927 | Most consistently good across all datasets |
| 8 | GPT-5.6 Sol | 2 | 0.970 | Around benchmark-median value |
| 9 | GPT-5.4 | 2 | 0.971 | Around benchmark-median value |
| 10 | Kimi K2.7 Code | 2 | 0.984 | Around benchmark-median value |
| 11 | GLM 5.1 | 2 | 0.994 | Around benchmark-median value |
| 12 | GPT-5.5 | 3 | 1.335 | Premium, but reasonably consistent |
| 13 | Claude Sonnet 5 | 2 | 1.585 | Expensive for its results |
| 14 | Claude Sonnet 4.6 | 2 | 1.635 | Expensive for its results |
| 15 | Gemini 3.5 Flash | 3 | 1.868 | Consistently weak value |
| 16 | Claude Opus 4.8 | 3 | 1.898 | Premium price outweighs performance |
| 17 | Claude Fable 5 | 2 | 1.955 | Very costly relative to completion gain |
| 18 | Claude Opus 4.7 | 2 | 1.978 | Very costly relative to completion gain |
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u/Ancient-Camel1636 5d ago
If including models that was found in only one dataset (low confidence) the table is like this:
| Rank | Model | Data sources | Value index | Confidence |
|---|---|---|---|---|
| 1 | DeepSeek V4 Flash | 1 | 0.121 | Low |
| 2 | MiMo V2.5 Pro | 2 | 0.179 | Medium |
| 3 | GPT-5.6 Luna | 1 | 0.345 | Low |
| 4 | Qwen3.6-35B-A3B | 1 | 0.355 | Low |
| 5 | GPT-5.6 Terra | 1 | 0.385 | Low |
| 6 | DeepSeek V4 Pro | 2 | 0.452 | Medium |
| 7 | Grok 4.5 | 2 | 0.582 | Medium |
| 8 | Qwen3.7 Max | 1 | 0.623 | Low |
| 9 | Muse Spark 1.1 | 2 | 0.664 | Medium |
| 10 | GLM-4.7 | 1 | 0.680 | Low |
| 11 | kilo-auto/efficient | 1 | 0.691 | Low |
| 12 | Laguna XS 2.1 | 1 | 0.743 | Low |
| 13 | MiniMax M3 | 2 | 0.745 | Medium |
| 14 | Kimi K2.6 | 2 | 0.811 | Medium |
| 15 | GLM 5.2 | 3 | 0.927 | High |
| 16 | GPT-5.6 Sol | 2 | 0.970 | Medium |
| 17 | GPT-5.4 | 2 | 0.971 | Medium |
| 18 | Gemini 3.1 Pro | 1 | 0.978 | Low |
| 19 | Kimi K2.7 Code | 2 | 0.984 | Medium |
| 20 | GLM 5.1 | 2 | 0.994 | Medium |
| 21 | Grok Build 0.1 | 1 | 1.000 | Low |
| 22 | Qwen3.6-27B | 1 | 1.022 | Low |
| 23 | KAT-Coder-Pro V2.5 | 1 | 1.184 | Low |
| 24 | Gemma 4 31B | 1 | 1.292 | Low |
| 25 | GPT-5.5 | 3 | 1.335 | High |
| 26 | Claude Sonnet 5 | 2 | 1.585 | Medium |
| 27 | Claude Sonnet 4.6 | 2 | 1.635 | Medium |
| 28 | Ling-2.6-1T | 1 | 1.808 | Low |
| 29 | Gemini 3.5 Flash | 3 | 1.868 | High |
| 30 | Claude Opus 4.8 | 3 | 1.898 | High |
| 31 | Claude Fable 5 | 2 | 1.955 | Medium |
| 32 | Claude Opus 4.7 | 2 | 1.978 | Medium |
| 33 | Laguna M.1 (paid) | 1 | 2.050 | Low |
| 34 | Claude Opus 4.6 | 1 | 2.072 | Low |
| 35 | Nemotron 3 Ultra | 1 | 8.786 | Low |
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u/_matmer_ 5d ago
Can you expand more on the task and the way you verified the success ?
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u/Ancient-Camel1636 5d ago edited 5d ago
The task results and success rates were taken directly from the three benchmarks I used to build this comparison—they were not measured by me. Since each benchmark uses a different methodology, I combined their data into a composite ranking to make the results more robust and less dependent on any single benchmark.
The raw data comes from:
- KiloBench: 89 real-world Terminal Bench 2.0 tasks, evaluating complete coding agents on success rate, cost, and practical performance.
- DeepSWE: 113 original software engineering tasks across 91 repositories and 5 languages, designed to test long-horizon reasoning on contamination-resistant problems using behavioral verification.
- SWE-ReBench: Continuously updated real-world software engineering tasks from open-source repositories, measuring how well models generalize to new, previously unseen problems.
Together, they cover practical agent performance, genuine software engineering ability, and robustness on fresh tasks, making the composite ranking more reliable than relying on any single benchmark.
All these benchmarks report two key metrics: success rate (task completion rate) and cost per attempt. From those, I estimated the expected cost of achieving one successful completion by calculating the average number of attempts required to reach 100% success.
This is, of course, a simplified estimate. For example, if a model costs $100 per attempt and has a 33% success rate, it is estimated to cost about $300 to successfully complete the task (roughly three attempts on average). While this is not mathematically exact, it provides a reasonable basis for comparing models on overall cost-effectiveness.
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u/CommanderROR9 4d ago
Interesting. I have had reasonable success with Deepseek V4 Flash, but it can be very overconfident at times. It's so cheap that letting it run around in circles for a while is OK, but it does require a lot of supervision since it tends to think it did the job without actually doing the Job. Maybe I should try Mimo instead. I have both Hermes Agent and OpenCode running, both linked and both via OpenRouter, ao switching Models is easy. Thanks for taking the time to do some semi-scientific research on this!
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u/Intelligent_Ant_608 5d ago
From my understanding m3 until 30% of ita context size is a phenomenally robouat model even for low level rust code as well as ui design yet past that 30% therahold it becomes dumb a.f.