InternLM Internvl2.5 38B vs xAI Grok 3 Fast Beta: Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing InternLM Internvl2.5 38B (internlm/internvl2.5-38b) vs xAI Grok 3 Fast Beta (x-ai/grok-3-fast-beta). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
InternLM Internvl2.5 38B (internlm/internvl2.5-38b) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for InternLM Internvl2.5 38B: Activate ephemeral prefix caching to slash input costs by 90% (down to 0.018/1M) or route via asynchronous Batch API for 50% off standard token rates.
xAI Grok 3 Fast Beta (x-ai/grok-3-fast-beta) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for xAI Grok 3 Fast Beta: Activate ephemeral prefix caching to slash input costs by 90% (down to 0.5/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing InternLM Internvl2.5 38B (API ID: internlm/internvl2.5-38b) vs xAI Grok 3 Fast Beta (API ID: x-ai/grok-3-fast-beta), InternLM Internvl2.5 38B offers lower standard input pricing at $0.18/1M tokens ($0.54/1M output), while InternLM Internvl2.5 38B leads in cached prefix economics at $0.018/1M tokens (90% discount). InternLM Internvl2.5 38B achieves a 0ms faster P90 time-to-first-token latency (195ms vs 195ms).
Gateway-synced rate ($0.18/$0.54 per 1M, flat 64K window). Verify upstream provider cache TTL and regional routing before high-volume batch runs.
Gateway-synced rate ($5/$25 per 1M, flat 128K window). Verify upstream provider cache TTL and regional routing before high-volume batch runs.
| Specification / FinOps Dimension | InternLM Internvl2.5 38B | xAI Grok 3 Fast Beta | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | internlm/internvl2.5-38b | x-ai/grok-3-fast-beta | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.18 / $0.54 | $5 / $25 | InternLM Internvl2.5 38B |
| Cache Read Price (per 1M) | $0.018/1M (90% Off) | $0.5/1M (90% Off) | InternLM Internvl2.5 38B |
| Context Window / Max Output | 64K In / 64K Out | 128K In / 64K Out | InternLM Internvl2.5 38B |
| P90 First-Token / Edge Latency | 195ms | 195ms | InternLM Internvl2.5 38B (-0ms) |
InternLM Internvl2.5 38B (internlm/internvl2.5-38b): OpenRouter gateway-synced model at $0.18/1M input, $0.54/1M output, $0.018/1M cached input (64K context window).
xAI Grok 3 Fast Beta (x-ai/grok-3-fast-beta): OpenRouter gateway-synced model at $5/1M input, $25/1M output, $0.5/1M cached input (128K context window).
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 InternLM Internvl2.5 38B to xAI Grok 3 Fast Beta
xAI Grok 3 Fast Beta (x-ai/grok-3-fast-beta): OpenRouter gateway-synced model at $5/1M input, $25/1M output, $0.5/1M cached input (128K context window). Verified P90 latency of 195ms.