Microsoft Phi 3 Medium 128K Instruct vs xAI Grok 4.3: Live Promos, Pricing, Hidden Fees & Latency
Microsoft Phi 3 Medium 128K Instruct (microsoft/phi-3-medium-128k-instruct) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for Microsoft Phi 3 Medium 128K Instruct: Activate ephemeral prefix caching to slash input costs by 90% (down to 0.01/1M) or route via asynchronous Batch API for 50% off standard token rates.
xAI Grok 4.3 (grok-4.3) 2026 Q4 Developer Promotion & Volume Credits
Official 2026 Q4 promotion for xAI Grok 4.3: Activate ephemeral prefix caching to slash input costs by 84% (down to 0.2/1M) or route via asynchronous Batch API for 50% off standard token rates.
In Etuki October 2026 FinOps telemetry comparing Microsoft Phi 3 Medium 128K Instruct (API ID: microsoft/phi-3-medium-128k-instruct) vs xAI Grok 4.3 (API ID: grok-4.3), Microsoft Phi 3 Medium 128K Instruct offers lower standard input pricing at $0.1/1M tokens ($0.2/1M output), while Microsoft Phi 3 Medium 128K Instruct leads in cached prefix economics at $0.01/1M tokens (90% discount). xAI Grok 4.3 achieves a 70ms faster P90 time-to-first-token latency (125ms vs 195ms).
Gateway-synced rate ($0.1/$0.2 per 1M, flat 128K window). Verify upstream provider cache TTL and regional routing before high-volume batch runs.
<200K: $1.25/$2.50 ($0.20 cache); >=200K full-request 2x cliff: $2.50/$5.00 ($0.40 cache). Batch discount is 20%; Priority tier 2x; US endpoint +10%.
| Specification / FinOps Dimension | Microsoft Phi 3 Medium 128K Instruct | xAI Grok 4.3 | Verified Advantage |
|---|---|---|---|
| Official Vendor API ID | microsoft/phi-3-medium-128k-instruct | grok-4.3 | Pinned Snapshot IDs |
| Standard Input / Output (per 1M) | $0.1 / $0.2 | $1.25 / $2.5 | Microsoft Phi 3 Medium 128K Instruct |
| Cache Read Price (per 1M) | $0.01/1M (90% Off) | $0.2/1M (84% Off) | Microsoft Phi 3 Medium 128K Instruct |
| Context Window / Max Output | 128K In / 64K Out | 1000K In / 128K Out | xAI Grok 4.3 |
| P90 First-Token / Edge Latency | 195ms | 125ms | xAI Grok 4.3 (-70ms) |
Microsoft Phi 3 Medium 128K Instruct
API ID: microsoft/phi-3-medium-128k-instruct • OpenRouter SyncedMicrosoft Phi 3 Medium 128K Instruct (microsoft/phi-3-medium-128k-instruct): OpenRouter gateway-synced model at $0.1/1M input, $0.2/1M output, $0.01/1M cached input (128K context window).
xAI Grok 4.3 high-speed reasoning model: $1.25/$2.50 (Cache $0.20/1M) short context; jumps to $2.50/$5.00 (Cache $0.40/1M) on long context.
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 Microsoft Phi 3 Medium 128K Instruct to xAI Grok 4.3
xAI Grok 4.3 high-speed reasoning model: $1.25/$2.50 (Cache $0.20/1M) short context; jumps to $2.50/$5.00 (Cache $0.40/1M) on long context. Verified P90 latency of 125ms.