A/B Testing PC Power Supply Calculator Examples
Worked examples showing how to compare PSU capacity and selected PSU load for two individual PC builds.
These examples use the calculator's method: estimate peak component demand, add a headroom margin, round up to a 50 W PSU size, and compare both builds against a selected PSU.
Mid-range gaming build versus efficient gaming build
A user is deciding whether both gaming configurations can use the same selected PSU size.
Input Summary
Configuration A
125 W CPU, 320 W GPU, 100 W other
Configuration B
65 W CPU, 220 W GPU, 90 W other
Headroom
30%
Selected PSU
750 W
Calculation Breakdown
- 1Configuration A demand125 + 320 + 100545 W
- 2Configuration A recommendationceil((545 × 1.30) / 50) × 50750 W
- 3Configuration B demand65 + 220 + 90375 W
- 4Configuration B recommendationceil((375 × 1.30) / 50) × 50500 W
- 5Selected PSU loads545 / 750 × 100; 375 / 750 × 10072.7%; 50.0%
Result Summary
Selected PSU loads
72.7%; 50.0%
A/B Testing PC Power Supply Calculator
Configuration A recommends 750 W and Configuration B recommends 500 W; their estimated loads on a 750 W PSU are 72.7% and 50.0%.
Compact office PC versus graphics workstation
A small office is evaluating separate PC designs per user rather than one shared power supply.
Input Summary
Configuration A office PC
65 W CPU, 0 W GPU, 75 W other
Configuration B workstation
150 W CPU, 300 W GPU, 110 W other
Headroom
25%
Selected PSU
650 W
Calculation Breakdown
- 1Office PC demand65 + 0 + 75140 W
- 2Office PC recommendationceil((140 × 1.25) / 50) × 50200 W
- 3Workstation demand150 + 300 + 110560 W
- 4Workstation recommendationceil((560 × 1.25) / 50) × 50700 W
- 5Selected PSU loads140 / 650 × 100; 560 / 650 × 10021.5%; 86.2%
Result Summary
Selected PSU loads
21.5%; 86.2%
A/B Testing PC Power Supply Calculator
The office PC recommends 200 W, while the workstation recommends 700 W; the selected 650 W unit is below the calculator's rounded workstation target.
Creator PC with future-upgrade margin versus current-spec build
A user compares a current build with a future-upgrade version that uses more margin.
Input Summary
Configuration A current-spec build
120 W CPU, 280 W GPU, 100 W other
Configuration B upgrade-minded build
120 W CPU, 280 W GPU, 100 W other
Headroom for A
15%
Headroom for B
40%
Selected PSU
650 W
Calculation Breakdown
- 1Base component demand120 + 280 + 100500 W
- 2Configuration A target500 × 1.15575 W
- 3Configuration A recommendationceil(575 / 50) × 50600 W
- 4Configuration B target500 × 1.40700 W
- 5Configuration B recommendationceil(700 / 50) × 50700 W
Result Summary
Configuration B recommendation
700 W
A/B Testing PC Power Supply Calculator
With identical 500 W component estimates, 15% headroom gives a 600 W recommendation and 40% headroom gives a 700 W recommendation.
How to Read Your Results
Estimated component power is the combined CPU, GPU, and other-component demand before headroom.
Recommended PSU wattage includes the selected headroom and is rounded upward to a 50 W increment.
Selected PSU load compares component demand, not wall power, with the PSU's rated output.
A higher load percentage does not by itself evaluate PSU quality, connector compatibility, or transient response.
Compare results per PC or workstation; separate users generally require separate PSUs.
Assumptions & Important Notes
- Component inputs are reasonable peak DC demand estimates.
- The selected PSU wattage is its rated continuous output capacity.
- The calculator rounds recommendations up to 50 W capacity increments.
- Examples are educational estimates rather than purchasing or electrical advice.
Related Examples
Frequently Asked Questions
Can both A and B use the same PSU wattage?
They can be compared against the same selected capacity, but connector requirements and the individual recommendation for each build still need checking.
Why can a 650 W PSU show a high load but still be below the recommendation?
The recommendation includes the chosen headroom, while the load output only compares estimated component demand with the PSU rating.
Can I enter 0 W for GPU power?
Yes, when the configuration has no discrete GPU or its power is intentionally included elsewhere.
Should office PCs and workstations use the same other-component estimate?
Not necessarily. Storage count, cooling, USB devices, expansion cards, and motherboard features can differ.
Ready to calculate your own result?
Use the live calculator with your own inputs, timing, and preferences.