SpaceXAI: Grok 4.20 vs NVIDIA: Nemotron 3.5 Lightning (free): Live Promos, Pricing, Hidden Fees & Latency
Verified 2026 FinOps benchmark comparing SpaceXAI: Grok 4.20 (x-ai/grok-4.20) vs NVIDIA: Nemotron 3.5 Lightning (free) (nvidia/nemotron-3.5-lightning:free). Simulate cache read multipliers, context cliffs, MAU bills, and P90 latency.
SpaceXAI: Grok 4.20 (x-ai/grok-4.20) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for SpaceXAI: Grok 4.20: Activate ephemeral prefix caching to slash input costs by 50% (down to $0.625/1M) or route via asynchronous Batch API for 50% off standard token rates.
NVIDIA: Nemotron 3.5 Lightning (free) (nvidia/nemotron-3.5-lightning:free) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for NVIDIA: Nemotron 3.5 Lightning (free): Activate ephemeral prefix caching to slash input costs by 50% (down to $0/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing SpaceXAI: Grok 4.20 (API ID: x-ai/grok-4.20) vs NVIDIA: Nemotron 3.5 Lightning (free) (API ID: nvidia/nemotron-3.5-lightning:free), NVIDIA: Nemotron 3.5 Lightning (free) offers lower standard input pricing at $0/1M tokens ($0/1M output), while NVIDIA: Nemotron 3.5 Lightning (free) leads in cached prefix economics at $0/1M tokens (50% discount). SpaceXAI: Grok 4.20 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 | SpaceXAI: Grok 4.20 | NVIDIA: Nemotron 3.5 Lightning (free) | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | x-ai/grok-4.20 | nvidia/nemotron-3.5-lightning:free | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $1.25 / $2.5 | $0 / $0 | NVIDIA: Nemotron 3.5 Lightning (free) |
| Cache Read Price (per 1M) | $0.625/1M (50% Off) | $0/1M (50% Off) | NVIDIA: Nemotron 3.5 Lightning (free) |
| Context Window / Max Output | 1953K In / 1758K Out | 977K In / 64K Out | SpaceXAI: Grok 4.20 |
| P90 First-Token / Edge Latency | 280ms | 280ms | SpaceXAI: Grok 4.20 (-0ms) |
Grok 4.20 is a reasoning model from SpaceXAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict
NVIDIA Nemotron 3.5 Lightning is an open mixture-of-experts model from NVIDIA, with 3B active parameters out of 30B total. It is suited for high-throughput agentic workloads and sp
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 SpaceXAI: Grok 4.20 to NVIDIA: Nemotron 3.5 Lightning (free)
NVIDIA Nemotron 3.5 Lightning is an open mixture-of-experts model from NVIDIA, with 3B active parameters out of 30B total. It is suited for high-throughput agentic workloads and sp Verified P90 latency of 280ms.