What power supply do I need for my graphics card?

For most gaming PCs, a good 750W power supply is the safe choice. It covers an RTX 5070 with room to spare. Step up to 850W for an RTX 5070 Ti, an RX 9070 XT or an RTX 5080, and to 1000W for an RTX 5090.

The wattage is only the first check. The connector, the standard (ATX 3.1) and the build quality matter just as much. This guide gives the number for each card, explains the cable, and lists three units that cost roughly £80 to £140.

What wattage power supply do I need for my graphics card?

The figure to use is the manufacturer's recommended system power. It already counts the processor, drives and fans, not only the card. Two sources agree on the main cards: NVIDIA for the RTX 5070 family, and Corsair's table for the rest.

NVIDIA's own 650W figure for the RTX 5070 assumes a Ryzen 9 9950X system, one of the hungriest gaming processors. A more modest CPU leaves you extra room.

The RTX 5070 Ti is the one card where the sources differ: 750W from NVIDIA, up to 850W from Corsair with a Ryzen 7 or 9. If you are buying a new unit anyway, take the 850W. The price gap is small, as you will see below.

Why is the recommended wattage so much higher than the card's power draw?

Because the card is not the only thing on the wire. An RTX 5070 draws about 250W in our performance data, but the processor, the motherboard, the drives and the fans all add to it. A Ryzen 7 7800X3D draws about 162W on its own.

The recommendation also builds in two margins:

• Short power spikes. A graphics card can briefly ask for more than its rated power. A PSU that sits right at the limit may shut the PC down.
• Headroom as the unit ages. A power supply delivers a little less over the years, and it runs quieter and cooler when it is not pushed to its maximum.

Here is a simple rule of our own, not a manufacturer figure. Add the card's watts, the processor's watts and about 100W for everything else. Multiply by 1.4, then round up to the next standard size.

For an RTX 5070 (250W) with a Ryzen 7 7800X3D (162W): 250 + 162 + 100 = 512W. Multiplied by 1.4, that is about 717W, so 750W. It lands one step above NVIDIA's 650W, which is exactly the margin we want.

Do I need an ATX 3.1 power supply, and what is 12V-2x6?

12V-2x6 is the small, high-power connector on RTX 50 cards. It replaces the older 12VHPWR. The practical rule is the same as before: the plug must be fully seated.

ATX 3.1 is the current power supply standard. It brought 12V-2x6 support, and it changed the hold-up time (how long the unit keeps going after a power cut) from 17 ms to 12 ms.

Do you need it? According to Corsair, no. An ATX 3.0 unit with a 12VHPWR cable works with an RTX 50 card if the plug is fully inserted. If you already own a good 3.0 unit, keep it. If you are buying new, ATX 3.1 is the smarter pick.

Do I need a native 12V-2x6 cable or can I use the 8-pin adapter?

Both work for the RTX 5070 and RTX 5070 Ti. NVIDIA ships these cards with an adapter that turns two 8-pin PCIe cables into the 12V-2x6 plug. You can also use a PCIe Gen 5 cable rated 300W or more.

A native cable is neater and uses a single connection on the PSU. The 2025 versions of the Corsair RM750e, RM850e and RM1000e are sold with a 12V-2x6 cable (ATX 3.1). Older stock of the same names can come with an adapter-style cable instead, so check that the listing says "2025" and "12V-2x6" before you buy.

What do Gold, Platinum and the quality tiers actually mean?

80 Plus and Cybenetics ratings measure efficiency: how much of the power drawn from the wall reaches your PC, and how much is lost as heat. Bronze, Silver, Gold, Platinum and Titanium go from lower to higher efficiency.

For gaming, Gold is the sweet spot. Platinum and Titanium cost more, and the saving on your electricity bill is small. A good Gold unit from a known brand is a better buy than a cheaper unit with no clear rating.

An efficiency rating is not a safety guarantee on its own. Look at the whole listing: ATX 3.1 compliance, a native cable, a warranty of several years (a long warranty is a decent quality signal), and recent reviews from sites that measure the unit.

Which power supply should I buy, and what does it cost in the UK?

All three units below are from the 2025 Corsair RMe range: fully modular, Cybenetics Gold, ATX 3.1, with a 12V-2x6 cable. Match the wattage to your card:

• 750W for an RTX 5070 or an RX 9070.
• 850W for an RTX 5070 Ti, an RX 9070 XT or an RTX 5080.
• 1000W for an RTX 5090.

Be careful with the name. The "RM750e (2025)" and the older ATX 3.0 RM750e are different products, which is why the search above includes "2025 ATX 3.1".

If you are building around an RTX 5060 or an RX 9060 XT, you do not need that much. A 650W Gold unit such as the MSI MAG A650GL, at roughly £60 to £75 depending on the shop, is a reasonable cheaper pick. For a full build around these cards, see our guides to the best gaming PC under £1,000 and the RTX 5060 vs RX 9060 XT.

Aiming higher? Our gaming PC under £1,500 and the RTX 5070 vs RX 9070 guides show where an 850W unit fits. The price shown on each card is the live one, refreshed daily, and can differ from the ranges in this guide.

Can I reuse my old power supply?

Sometimes. Keep it only if three things hold: the wattage matches the table above, it has the PCIe connectors your card needs, and it is still in good condition.

Count the connectors. A card that wants three 8-pin cables will not run on a unit that only has two. If you have the adapter option for an RTX 5070 or 5070 Ti, you need two free 8-pin PCIe outputs.

A unit that is several years old and was already working hard in your last PC is a candidate for replacement. A new power supply is a small part of a build, and it protects everything else in it.

Memory is the other part that quietly shapes a build. Our guide on how much RAM you need for gaming covers it. If you want us to match a power supply to your exact card and processor, the assistant above does it in a few seconds.

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