3C COMPASS LAB
Five open models turn measurements into comparison targets. Every result exposes its equation, intermediate values, version, and the hardware-specific check that remains.
charger
power-bank
phone-storage
laptop-capacity
display-link
Calculated examples
Every output below is computed at build time by the same pure function used in the interactive page. These are analytical examples, not claims of physical measurement.
| Scenario | Measured inputs | Calculated output | Decision lesson |
|---|---|---|---|
| charger65W laptop plus 20W phonecharger-budget-v2.0 | 65W primary device, 20W secondary load, 15% headroom, two USB-C ports | 100W tier97.75W calculated budget; 100W market tier; 65W minimum primary-port allocation | The total label is useful only when the charger's two-port allocation preserves 65W for the laptop. |
| charger30W tablet plus 15W travel loadcharger-budget-v2.0 | 30W primary device, 15W secondary load, 10% headroom, two USB-C ports | 65W tier49.5W calculated budget; 65W market tier; 60W cable class | A 45W sum becomes a 65W buying target once simultaneous use and modest headroom are included. |
| power-bank10,000mAh weekend phone reservepower-bank-energy-v2.0 | 10,000mAh at 3.7V, 85% conversion efficiency, 17Wh phone battery, 1.5-charge target | 31.45Wh usable37Wh rated; 31.45Wh estimated usable; 1.85 calculated full charges | The printed mAh number overstates energy delivered at the USB output because conversion has a cost. |
| power-bank27,000mAh laptop reservepower-bank-energy-v2.0 | 27,000mAh at 3.7V, 82% efficiency, 60Wh laptop battery, one-charge target | 99.9Wh rated99.9Wh rated; 81.92Wh estimated usable; 21.92Wh reserve after the target | A capacity near 100Wh can cover the energy target, but useful laptop charging still requires sufficient USB-C output power. |
| phone-storageSix-month measured storage trendphone-storage-forecast-v2.0 | 92GB used, 6 observed months, 3.5GB monthly retained growth, 30 months remaining, 24GB reserve | 256GB tier197GB projected used; 221GB including reserve; 256GB retail tier | A measured 128GB user can still justify 256GB when retained growth and an update reserve are projected across ownership. |
| phone-storageVideo-heavy two-year forecastphone-storage-forecast-v2.0 | 180GB used, 4 observed months, 8GB monthly retained growth, 24 months remaining, 48GB reserve | 512GB tier372GB projected used; 420GB including reserve; 512GB retail tier | Local video growth, not cloud-plan size, drives this phone from a 256GB starting point to a 512GB target. |
| laptop-capacityMeasured office and creative laptoplaptop-capacity-v2.0 | 13GB peak memory, 3GB sustained swap, 310GB used storage, 90GB annual growth, four years | 24GB / 1000GB24GB memory tier; 670GB projected used; 1000GB storage tier | Sustained swap makes the memory requirement visible, while replaceable storage can take the later upgrade risk. |
| laptop-capacityFixed developer workstation capacitylaptop-capacity-v2.0 | 26GB peak memory, 6GB sustained swap, 740GB used storage, 220GB annual growth, four years | 48GB / 2000GB48GB memory tier; 1620GB projected used; 2000GB storage tier | When neither capacity is replaceable, the observed working set and retained project growth both belong in the original order. |
| display-linkDual 4K 60Hz over four HBR3 lanesdisplay-link-budget-v2.0 | Two 3840x2160 displays, 60Hz, 8 bits per color channel, four lanes, HBR3 | 96.77% payload25.08Gbps estimated demand; 25.92Gbps payload; 96.77% utilization; check | The uncompressed estimate nearly fills HBR3, so exact timing, DSC, host display count, and dock routing must be checked. |
| display-link3440x1440 100Hz 10-bit ultrawidedisplay-link-budget-v2.0 | One 3440x1440 display, 100Hz, 10 bits per color channel, four lanes, HBR3 | 60.2% payload15.6Gbps estimated demand; 25.92Gbps payload; 60.2% utilization; pass | The link budget has room, but the result still cannot prove that the host, cable, dock, and monitor expose the selected mode. |
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