Gemini 3.8 Flash TTS vs Union Alpha (Stealth)
A direct, empirical evaluation of Gemini 3.8 Flash TTS (Google DeepMind) against Union Alpha (Stealth) (OpenRouter & OpenCode).
Gemini 3.8 Flash TTS
Developed by Google DeepMind · Proprietary Multimodal Acoustic Flow Matching Transformer parameters
High-fidelity expressive podcasts, interactive video game dialogues, scripted multi-speaker conversations, and prompt-designed custom character voices.
Union Alpha (Stealth)
Developed by OpenRouter & OpenCode · Multi-Model Ensemble Mixture parameters
Terminal coding agents, pull-request synthesis, multi-model consensus verification, and zero-cost autonomous refactoring.
| Metric | Gemini 3.8 Flash TTS | Union Alpha (Stealth) |
|---|---|---|
| SWE-bench Verified | 64.2% | 74.2% |
| MMLU-Pro | 88.5% | 89.8% |
| MATH-500 | 91% | 95.4% |
| Context Window | 128,000 characters input dialogue script | 256,000 tokens |
| Input Pricing (per 1M) | $0.15 | $0.00 |
| Output Pricing (per 1M) | $15.00 | $0.00 |