Buying an RTX 3080? Check your PSU and case first

Before you order a GeForce RTX 3080, check three things in your PC: the exact card’s power recommendation, its power cables, and the space in your case. NVIDIA announced the GeForce RTX 3080 was available from 17 September 2020 in its release article . The figures below describe its Founders Edition; partner cards need their own specification check.

NVIDIA’s launch-era RTX 3080 specifications and compatibility guide lists 320 W of graphics-card power and 750 W of recommended system power for the Founders Edition. The 750 W recommendation is based on a PC with an Intel Core i9-10900K. NVIDIA says a lower-rated supply may work depending on system configuration and advises checking with the power-supply vendor. The same page says its figures describe NVIDIA’s reference design and may vary by add-in-card manufacturer.

Check the recommendation for your whole PC

The 320 W figure describes the graphics card. The 750 W figure is NVIDIA’s recommended power-supply capacity for the system configuration it specifies. They answer different questions: the card’s listed power and the recommended capacity for the PC around it.

Find the exact model of your power supply, then compare it with the recommendation for the exact RTX 3080 model you plan to buy. If your supply is below 750 W, NVIDIA’s note leaves room for different configurations; it does not establish that every lower-rated supply will work. Check with the power-supply maker using your actual processor and other components before ordering.

Do not use a model name alone as a compatibility verdict. Board partners planned custom cards alongside NVIDIA’s Founders Edition, including stock-clocked and factory-overclocked versions. Use the manufacturer’s specifications for the card’s full model number, including any “OC” suffix.

Confirm the power cables

The Founders Edition uses a compact 12-pin connector. NVIDIA said it would include an adapter so the card could work with existing power supplies. Its compatibility guide also calls for two dedicated PCIe 8-pin cables coming separately from the power supply. NVIDIA described the connector and adapter in its 26 August design note .

Check what cables your exact supply has before you buy. Two plugs at the graphics-card end are not the same check as confirming two separate cables from the supply. If your planned card is a partner model, follow that card maker’s connector and cable instructions rather than assuming the Founders Edition adapter applies.

Measure the case against the exact card

NVIDIA’s compatibility guide lists the Founders Edition at 285 mm long, 112 mm wide and two slots tall. Check your case’s maximum graphics-card clearance and whether that measurement accounts for its installed front fans, radiator or drive cage. Leave room for the card’s width, adjacent slots and the power cable near the side panel too.

For example, if a case lists 300 mm of clearance in your actual fan configuration, the Founders Edition’s listed length leaves 15 mm of nominal length clearance. That comparison is useful only if the case’s measurement describes the space available to the card. It says nothing about a partner model that is longer or thicker.

Make the check before checkout

Write down the exact card model, the power-supply model, and the case model. Compare the card maker’s power and cable requirements with the PSU maker’s guidance for your build. Then compare the card’s length, width and slot thickness with the space your case actually has.

If one manufacturer’s specification does not answer a compatibility question, ask before ordering. The Founders Edition’s 750 W recommendation and 285 mm length are useful reference points; the exact card and the rest of your PC determine whether they apply.

This guide uses NVIDIA materials available by 22 September 2020 and is a specifications-based checklist, not an independent power test or a guarantee of fit.