ADC API Gateway Throughput Calculator
Size an API gateway's request ceiling from per-request CPU cost, with uplifts for authentication, transformation and cache hits.
Inputs
Maximum Sustainable Request Rate
102,269rps
CPU Utilisation at the Given Rate
11.7%
Throughput
768.0Mbps
Effective CPU per Request
156.5µs
Headroom Before Saturation
90,269rps
Step by step
Values used
Requests per second = 12,000 rps; Average response payload = 8 KB; Base CPU per request = 120 µs; CPU cores available = 16 cores; Validating a JWT or API key per request = Yes; Request/response transformation enabled = Yes; Responses served from the gateway cache = 30 %
ADC API Gateway Throughput
effective CPU = base CPU × auth uplift × transform uplift, blended so cache hits cost 15% of a full request; max rps = cores × 1,000,000 µs ÷ effective CPU.
Maximum Sustainable Request Rate
= 102,269 rps
CPU Utilisation at the Given Rate
= 11.7
Throughput
= 768.0 Mbps
Effective CPU per Request
= 156.5 µs
Headroom Before Saturation
= 90,269 rps
How it works
An API gateway spends a near-constant amount of CPU per request on parsing, routing and policy evaluation, so its ceiling is the available core-microseconds divided by that cost. Cache hits skip the upstream call and most of the policy chain, so they are blended in at a fraction of the full cost. JWT validation and body transformation together can double the per-request cost, which is why a gateway benchmarked with a pass-through route delivers half that number once real policies are attached.
Formula
ADC API Gateway Throughput
effective CPU = base CPU × auth uplift × transform uplift, blended so cache hits cost 15% of a full request; max rps = cores × 1,000,000 µs ÷ effective CPU.
- baseUs
- Routing and proxying cost, ×1.25 for token validation and ×1.4 for payload transformation
- cachedShare
- Fraction of requests answered without touching the upstream
Frequently Asked Questions
How is ADC API Gateway Throughput calculated?
effective CPU = base CPU × auth uplift × transform uplift, blended so cache hits cost 15% of a full request; max rps = cores × 1,000,000 µs ÷ effective CPU. An API gateway spends a near-constant amount of CPU per request on parsing, routing and policy evaluation, so its ceiling is the available core-microseconds divided by that cost. Cache hits skip the upstream call and most of the policy chain, so they are blended in at a fraction of the full cost.
Why does ADC API Gateway Throughput matter?
JWT validation and body transformation together can double the per-request cost, which is why a gateway benchmarked with a pass-through route delivers half that number once real policies are attached.
What values do I need to enter?
This calculator takes 7 inputs: Requests per second, Average response payload, Base CPU per request, CPU cores available, Validating a JWT or API key per request, Request/response transformation enabled, Responses served from the gateway cache. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
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