Upstage: Solar Pro 4 vs OpenAI: GPT-5.6 Terra Pro: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing Upstage: Solar Pro 4 (upstage/solar-pro4) vs OpenAI: GPT-5.6 Terra Pro (openai/gpt-5.6-terra-pro). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
Upstage: Solar Pro 4 (upstage/solar-pro4) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Upstage: Solar Pro 4: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.045/1M) or route via asynchronous Batch API for 50% off standard token rates.
OpenAI: GPT-5.6 Terra Pro (openai/gpt-5.6-terra-pro) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 75% automatic prefix caching ($0.50/1M), 50% off 24-hour Batch API completions ($1/$5), and up to $150,000 in OpenAI/Azure Foundry credits via Microsoft for Startups Founders Hub (no VC funding required for initial tiers).
In Etuki October 2026 FinOps telemetry comparing Upstage: Solar Pro 4 (API ID: upstage/solar-pro4) vs OpenAI: GPT-5.6 Terra Pro (API ID: openai/gpt-5.6-terra-pro), Upstage: Solar Pro 4 offers lower standard input pricing at $0.09/1M tokens ($0.36/1M output), while Upstage: Solar Pro 4 leads in cached prefix economics at $0.045/1M tokens (50% discount). Upstage: Solar Pro 4 achieves a 0ms faster P90 time-to-first-token latency (280ms vs 280ms).
Auto-discovered via live global telemetry registry.
Auto-discovered via live global telemetry registry.
| Specification / FinOps Dimension | Upstage: Solar Pro 4 | OpenAI: GPT-5.6 Terra Pro | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | upstage/solar-pro4 | openai/gpt-5.6-terra-pro | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.09 / $0.36 | $2 / $12 | Upstage: Solar Pro 4 |
| Cache Read Price (per 1M) | $0.045/1M (50% Off) | $1/1M (50% Off) | Upstage: Solar Pro 4 |
| Context Window / Max Output | 512K In / 128K Out | 1025K In / 125K Out | Upstage: Solar Pro 4 |
| P90 First-Token / Edge Latency | 280ms | 280ms | Upstage: Solar Pro 4 (-0ms) |
Solar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in
GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality response
Real-Time Stack Cost & Hidden-Fee Simulator (MAU / Token / Egress / GMV)
Calibrated with Reddit r/FinOps & r/devops telemetry: Includes Context Caching, Bandwidth Egress, and MoR Tax
🛰️Switch from Upstage: Solar Pro 4 to OpenAI: GPT-5.6 Terra Pro
GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), served with `reasoning.mode` set to `pro` for higher-quality response Verified P90 latency of 280ms.