DeepSeek Chat V3 vs OpenAI GPT-5.6 Terra (Legacy): Live Promos, Pricing, Hidden Fees & Latency
DeepSeek Chat V3 (deepseek/deepseek-chat-v3) — Automatic Disk KV Cache (0.014/1M) & Off-Peak Promo
DeepSeek-V4 Pro (1.6T MoE) automatically caches repeated 64-token prompt prefixes on NVMe storage at $0.022/1M off-peak input tokens (vs $0.66 off-peak base) with zero code changes required, plus off-peak UTC scheduling discounts.
OpenAI GPT-5.6 Terra (Legacy) (gpt-5.6-terra) Startup Credits & Batch API 50% Off Promo
OpenAI GPT-6.1 Sol ($2/$10 base rate) qualifies for immediate 95% automatic prefix caching ($0.10/1M), 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 DeepSeek Chat V3 (API ID: deepseek/deepseek-chat-v3) vs OpenAI GPT-5.6 Terra (Legacy) (API ID: gpt-5.6-terra), DeepSeek Chat V3 offers lower standard input pricing at $0.14/1M tokens ($0.28/1M output), while DeepSeek Chat V3 leads in cached prefix economics at $0.014/1M tokens (95% discount). DeepSeek Chat V3 achieves a 20ms faster P90 time-to-first-token latency (145ms vs 165ms).
Automatic disk-KV caching cuts repeated prompt input costs by 90% ($0.014/1M) with zero manual configuration. Search/Fetch API billed separately at $0.75/1K calls.
Flat context pricing ($2.00/$12.00, Cache $0.20/1M); consider migrating to GPT-6.1 Sol ($2.00/$10.00, Cache $0.10/1M) for 95% cache savings.
| Specification / FinOps Dimension | DeepSeek Chat V3 | OpenAI GPT-5.6 Terra (Legacy) | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | deepseek/deepseek-chat-v3 | gpt-5.6-terra | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.14 / $0.28 | $2 / $12 | DeepSeek Chat V3 |
| Cache Read Price (per 1M) | $0.014/1M (95% Off) | $0.2/1M (90% Off) | DeepSeek Chat V3 |
| Context Window / Max Output | 1050K In / 128K Out | 400K In / 128K Out | DeepSeek Chat V3 |
| P90 First-Token / Edge Latency | 145ms | 165ms | DeepSeek Chat V3 (-20ms) |
DeepSeek Chat V3 (Oct 17, 2026 Pareto Update) delivers 77.0% on DeepSWE v1.1, 60.5% on Automation-Bench, native Search/Fetch API ($0.75/1K calls), and 90% auto disk-KV cache savings.
OpenAI GPT-5.6 Terra router catalog tier ($2.00/$12.00 per 1M, 400K flat context window, $0.20 cache read).
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 DeepSeek Chat V3 to OpenAI GPT-5.6 Terra (Legacy)
OpenAI GPT-5.6 Terra router catalog tier ($2.00/$12.00 per 1M, 400K flat context window, $0.20 cache read). Verified P90 latency of 165ms.