A/B Testing CPU Requirement (Annual) Calculator FAQ
Answers to common questions about estimating A/B testing CPU hours, request volume and active CPU capacity.
This FAQ explains the inputs, outputs and assumptions used to estimate CPU processing requirements for a server-side A/B testing program.
General CPU Requirement Questions
Basic questions about the purpose and scope of the estimate.
What is an A/B testing CPU requirement?
It is the CPU processing work associated with experiment-related request handling, such as assignment, evaluation and logging.
What does the annual CPU requirement result mean?
It estimates aggregate CPU hours used by the planned experiments over one year.
Is this calculator only for server-side A/B tests?
It is most applicable to server-side processing, where experiment logic consumes application or service CPU time on requests.
Does the calculation include all infrastructure costs?
No. It excludes costs such as storage, network transfer, databases, queues and fixed infrastructure unless included in the CPU-per-request input.
Inputs and Formula
Questions about traffic, duration, variants and CPU time inputs.
How are tested requests per experiment estimated?
Annual visitors are multiplied by tested requests per visitor, traffic allocation and the test duration as a share of 365 days.
What traffic allocation should I enter?
Enter the percentage of eligible traffic expected to pass through a typical experiment during its active period.
Why is test duration included in the formula?
It determines what fraction of annual traffic is exposed to one average experiment.
Should I count the control as a variant?
Yes. Enter the total number of variants, including the control.
What CPU time should I use per tested request?
Use a representative estimate of CPU work caused by the experiment path, preferably based on profiling or production-like measurements.
Results and Capacity Interpretation
Questions about interpreting CPU hours and CPU-core outputs.
What is the difference between CPU hours and CPU cores?
CPU hours are total processing work over time. Average active CPU cores describe the average rate of that work during an active test.
Why is average active CPU capacity lower than peak capacity may be?
The result assumes traffic arrives evenly. Real traffic may cluster by time of day, campaign, geography or event.
Can I add annual CPU hours for concurrent tests?
Annual CPU hours can be aggregated across tests, but concurrent tests are especially relevant when assessing instantaneous or peak capacity.
Do more variants increase total CPU hours?
Not by themselves when each request is assigned to one variant. However, added evaluation complexity can increase CPU time per request.
Accuracy and Planning Limits
Questions about assumptions and ways to improve an estimate.
How accurate is the A/B testing CPU estimate?
It is an estimate whose usefulness depends mainly on how representative the traffic and CPU-per-request inputs are.
What can make actual CPU usage higher?
Traffic peaks, retries, cache misses, complex targeting, detailed logging, overlapping experiments and additional application work can increase actual usage.
How can I improve the estimate?
Measure CPU cost under representative traffic, separate experiment work from baseline work, and reassess after meaningful implementation changes.
Should I include headroom in the calculator input?
The calculator reports estimated processing work. Headroom is usually considered separately when evaluating operational capacity and resilience.
How are annual CPU hours for A/B testing calculated?
The calculator estimates requests in one test, applies CPU time per request, converts to CPU hours and multiplies by the number of tests per year.
Explore Related Questions
Ready to see what you can calculate?
Open the calculator and get personalized results in seconds.