Google Vertex AI in Practice

Provisioned Throughput on Vertex AI: Commitment, Cost, and When It Pays Off

Pay-as-you-go shares capacity with everyone else. Provisioned Throughput reserves it for you — at a fixed fee, for a fixed term, with real constraints on where and which models it covers.

Claude 3P 101 · Updated July 2026 · Unofficial guide

Google defines Provisioned Throughput as "a fixed-cost, fixed-term subscription available in several term-lengths that reserves throughput for supported generative AI models." For Claude as a partner model, the pitch is simple: your reserved capacity is yours, and provisioned requests "are prioritized over the standard pay-as-you-go requests." You specify the model and the locations; Google guarantees the throughput. It converts a variable bill and variable availability into a fixed bill and predictable capacity — which is either exactly what you need or an expensive way to pay for idle reservation, depending on your traffic shape.

What you're actually buying

Three properties define the product:

The constraints that shape your architecture

Two documented limits matter before you talk to sales. First, Provisioned Throughput requires regional endpoints — it is not supported on the global endpoint or the us/eu multi-region endpoints, which are pay-as-you-go only. If you built on the global endpoint (a sensible default otherwise), adopting reserved capacity means re-pointing that workload to a specific region. Second, model coverage is a specific list: Google's pricing page currently names Claude Haiku 4.5, Sonnet 4.6, Sonnet 4.5, Sonnet 4, Opus 4.6, Opus 4.5, Opus 4.1, and Opus 4 as supported for Provisioned Throughput. Notably, that published list does not include the newest generation (Opus 4.8, Sonnet 5, Fable 5) as of this writing — check the current pricing page and confirm with your Google account team before assuming your target model qualifies.

A break-even framework (method, not magic numbers)

Because the subscription price is quoted, not public, do the comparison yourself. The logic:

  1. Compute your on-demand baseline. Monthly input and output tokens at the applicable rates — and use regional rates, since that's what provisioned throughput forces: regional endpoints carry a 10% premium over global list prices (for example, Opus 4.6-class models list at $5 input / $25 output per million tokens on the global endpoint). Include prompt-caching savings you already achieve.
  2. Get the quote for the throughput level that covers your peak, for each term length on offer.
  3. Find the utilization break-even. Fixed fee ÷ your effective on-demand cost per unit of traffic = the sustained volume at which the subscription is cheaper. If your realistic average utilization of the reserved capacity sits well above that point, the reservation pays; if your traffic is spiky with a low average, you are buying priority, not savings — which may still be worth it, but call it what it is.
  4. Model the hybrid. A common pattern is reserving for the steady base load and letting bursts spill to pay-as-you-go (or shifting deferrable work to Google's Vertex batch prediction for Claude at 50% of on-demand). Compare that blend against 100% on-demand and 100% reserved.
Rule of thumb: flat, high, business-critical traffic → provisioned throughput earns its keep. Spiky or experimental traffic → stay on-demand, fix your 429 story with quota increases and retries, and revisit once the load flattens.

Where to go next

Work the general economics in the provisioned-throughput payoff analysis, compare with committed-use negotiation in committed use on Vertex, and revisit endpoint strategy in the endpoint decision guide — reserved capacity and the global endpoint are mutually exclusive.

Sources