Reference · data reviewed 2026-11-10
Methodology
WattWise is a planning model. CPU and GPU limits come from manufacturer pages, and each part page names the page the figure came from. Platform watts are allowances. Transient behavior comes from the ATX and PCIe specs, not from a made-up spike per card. CPU data was reviewed 2026-11-10.
Profiles
Let idle be a single desktop allowance (15 W for a CPU package, 12 W for a GPU board). Let max be the CPU package limit or the GPU board power. At utilization u, from 0 to 1, draw is (idle + (max − idle) × u) × (1 + offset). The offset is the expert slider, from −40% to +40%, and it is your assumption.
- Gaming. GPU utilization is 100%, so the card is planned at its rated board power. CPU utilization is solved so the draw equals vendor base power (TDP or Processor Base Power). A 120 W Ryzen 7 9800X3D is planned at 120 W, not at its 162 W PPT.
- Power limits. Both parts at 100% before the offset. This is the overlap of an all-core CPU load and a power-limited GPU.
- Custom. You set both utilizations.
Vendors do not publish a separate in-game average for these cards, so the gaming estimate uses rated board power. That choice is conservative for the GPU. It is not a claim that every game holds the power limit.
Platform allowances
These are planning allowances, not measurements of a named part. Each one is a round figure inside the range component vendors and the ATX platform budget use for that class of device. Expert mode exists so you can raise or lower the count. Do not read them as a lab result.
| Item | Watts | Method |
|---|---|---|
| Motherboard, chipset, VRM overhead, and onboard devices | 35 | Flat planning allowance for the rest of the board once the CPU package and memory modules are counted separately. |
| DDR4 module, per stick | 3 | Planning allowance per module. JEDEC does not publish one gaming wattage. |
| DDR5 module, per stick | 5 | Planning allowance per module, higher than DDR4 because DDR5 modules include on-DIMM power management. |
| NVMe SSD, active | 6 | Planning allowance for an active consumer NVMe drive. Idle is lower; a sustained write can be higher. |
| SATA SSD, active | 3 | Planning allowance for an active 2.5-inch SSD. |
| 3.5-inch hard drive, spinning | 8 | Planning allowance for a spinning 7200 rpm desktop drive, not the spin-up peak. |
| Case or radiator fan | 2 | Planning allowance for a 120 mm or 140 mm case fan. A high-speed fan can draw more. |
| AIO pump | 6 | Planning allowance for a consumer liquid-cooler pump, not including radiator fans. |
| RGB device | 3 | Planning allowance per lit fan or short strip. Dense strips can draw more. |
| USB device | 4.5 | USB 3.x unit load allowance (4.5W). A phone or external drive can draw more; a mouse draws less. |
| Extra PCIe card | 10 | Planning allowance for a capture card, sound card, or NIC. A second graphics card does not belong in this line. |
| CPU package idle allowance | 15 | Single desktop idle allowance used only to anchor the utilization slider. It is not a per-SKU measurement. |
| GPU board idle allowance | 12 | Single desktop idle allowance used only to anchor the utilization slider. Multi-monitor high-refresh idle can be higher, especially on Intel Arc. |
PSU sizes
The displayed load is the sum of the lines, rounded to the nearest watt. Standard sizes are 300, 400, 450, 500, 550, 600, 650, 700, 750, 850, 1000, 1200, 1300, 1500, and 1600 W. The minimum is the smallest size at or above load ÷ 0.80. The efficiency size is the smallest size at or above load ÷ 0.50. If the target is above 1600 W, the tool says so instead of inventing a larger catalog.
Connector budgets use 75 W for the slot, 150 W per 8-pin, and 75 W per 6-pin. A Gen 5 cable adds its rated wattage (300, 450, or 600) plus the slot. A path within 15 W of the board power is marked tight.
CPU limit status
- Published. Intel Processor Base Power and Maximum Turbo Power, transcribed from Intel ARK.
- Derived. AMD prints Default TDP. Stock PPT for the class is the socket step 65→88, 105→142, 120→162, 170→230, which is 1.35× TDP. The Ryzen 7 9700X note also records AMD's optional 105 W cTDP mode. The model uses the stock 65 W / 88 W limits.
- Reported. The Ryzen 9 9950X and 9950X3D are 170 W TDP on AMD's pages. Stock PPT is 200 W in reviewer documentation of AMD's default, including Puget Systems' default-PPT column, not 230 W. Those two parts are marked reported.
Arrow Lake parts in this set do not use hyper-threading, so the Core Ultra 9 285K is 24 cores and 24 threads. Its base and turbo figures are 125 W and 250 W.
Transients
From Intel ATX design guide 336521, Table 3-3, for a PSU above 450 W with a 12V-2x6 connector: 200% for 100 µs, 180% for 1 ms, 160% for 10 ms, 120% for 100 ms, then 100% continuous, at the duty cycles in that table. Without that connector the column is 150%, 145%, 135%, 110%, and 100%. Card-side excursions for cards above 75 W reach 3× sustained power at or under 100 µs (Table 3-1). Sense-pin cable limits are 600, 450, 300, or 150 W (Table 3-6). The full explanation is the transient guide. Source: document 336521.
80 PLUS payback
These are certification floors at the named load points, not the efficiency curve of a particular unit. 80 PLUS Ruby exists in the current program and is not modeled here. Below the lowest published point, WattWise holds the nearest published efficiency instead of inventing a lower-load curve. Source: CLEAResult 80 PLUS 115V internal requirements. Between two published load points, efficiency is linear. Outside them, the nearest published point is held. Annual wall energy is load ÷ efficiency × hours per year ÷ 1000, with a 365-day year. Savings are the difference in annual cost. Payback is the price difference you type, divided by yearly savings. If the candidate does not save energy, there is no payback. Ruby is in the current program and is not modeled.
| Tier | 10% | 20% | 50% | 100% |
|---|---|---|---|---|
| 80 PLUS White (Standard) | — | 80% | 80% | 80% |
| 80 PLUS Bronze | — | 82% | 85% | 82% |
| 80 PLUS Silver | — | 85% | 88% | 85% |
| 80 PLUS Gold | — | 87% | 90% | 87% |
| 80 PLUS Platinum | — | 90% | 92% | 89% |
| 80 PLUS Titanium | 90% | 92% | 94% | 90% |
Electricity
Daily energy is watts × hours ÷ 1000. A month in the tool is 30 days. A year is 365. State rates are EIA Electric Power Monthly Table 5.6.A, residential, August 2026, released October 23, 2026. 2026 values are preliminary. EIA's figure is average revenue per kilowatt-hour, not a tariff and not a time-of-use price. The US residential average in that table is 18.16¢. Custom rates are whatever currency you type. There is no exchange-rate service.
UPS
Runtime in hours is battery watt-hours × inverter efficiency ÷ load watts. Amp-hours × nominal volts gives watt-hours. The default 85% efficiency and 0.95 power factor are labeled assumptions for a PC with active PFC, and both fields are editable. Suggested watt rating is the next standard size at or above 1.25 × load. Suggested VA covers load ÷ power factor. The 25% is planning headroom so the UPS is not specified at its ceiling.
GPU pages
Every GPU page uses this same model. The three pairing CPUs are the Ryzen 5 9600X, Ryzen 7 9800X3D, and Ryzen 9 9950X, with the same platform as Basic mode. Each answer uses that card's own wattage.