Best PSU for RTX 4090 in 2024: High-wattage power supplies

The RTX 4090 is a powerful graphics card, making many question if they need an upgrade in the power department

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If you just got your hands on the flagship RTX 4090, then you are likely looking for the best PSU to get the most out of it and keep it purring for years to come. This card needs a little more power than its predecessor, with Nvidia recommending 850W at a minimum – the best PSUs for the 4090 will need a touch above that. If you’re planning on upgrading your gear in the future, or are shopping for the more powerful 4090 SKUs, then you should aim for 1000W or more for extra longevity and headroom.

We’ve put together a list of some high-wattage power supply options for the RTX 4090, for a range of applications. Whilst power supply units are one of the less complicated components of a PC, some of these PSUs have rather fancy features that may be overkill for some PC builders. To balance out our rankings, we’ve included some more affordable solutions for your 4090 power supply. So regardless of whether you rely on budgets or build quality, our picks for the best 4090 power supply will be sure to satisfy!

RTX 4090 Power Requirements

For those building a PC for the first time: bravo! You’ve gone for the don of GPUs. The RTX 4090 is the flagship GPU from NVIDIA, and it is one powerful piece of hardware. This graphics process sits with an impressive 450W TDP, 100W higher than its predecessor, the 3090. Though that seems good at first, it can mean those who were already pushing their build to the limits may need an upgrade.

NVIDIA recommends a minimum of an 850W PSU, but we think you should aim just a little higher to prolong your investment in the long term. Some power recommendations can change depending on the AIB model of your GPU, so always double-check with the manufacturer’s specifications so that you never end up disappointed.

Best PSU for the RTX 4090: MSI Ai1300P ATX 3

MSI MEG Ai1300P PCIE 5 & ATX 3.0

MSI MEG Ai1300P PCIE 5 & ATX 3.0

Wattage

1300W

Efficiency

Platinum

Modularity

Fully-modular

ATX 3.0

Yes

Pros
  • ATX 3 / PCIE 5
  • Very efficient
  • Plenty of spare wattage
Cons
  • Overkill
  • Expensive

This 1300W ATX 3 PSU could be considered overkill: it is way more power than is actually required for the 4090. But as we said, a new PSU is an investment for the future. You never know when an even more powerful GPU is going to come along, after all. Aside from that, it is one of the best PSUs on the market for those looking to build the fastest gaming PCs. The advantage of such a quality PSU and high wattage is near silence. It offers complete support for the latest ATX 3.0 specification, an 80+ Platinum rating, 100% Japanese 105°C capacitors, and full modularity. If you are looking to future-proof your PC build, then the MSI Ai1300P is our top 4090 power supply!

Best ATX 2 PSU for 4090: ASUS ROG Thor 1000W Platinum

ASUS ROG Thor 1000W Platinum II

Wattage

1000W

Efficiency

Platinum

Modularity

Fully-Modular

Pros
  • Quality, reliable, and efficient
  • OLED panel
  • Winning design
Cons
  • Expensive
  • Requires an adapter for the 4090

For an ATX 2.0 PSU that far surpasses the 4090’s PSU requirements, the ASUS ROG Thor is a suitably godlike choice, and worthy of a top spot as the best power supply units on the market! Matching the 1000W wattage that we recommend, this power supply also comes with an 80+ Platinum rating for hyper-efficient power management. The built-in OLED panel allows you to monitor power usage in real time, and the ROG Thor also comes with a 0db cooling system that utilize IPX5 fans for silent and cool running. Though it is pricier than other models and requires an adapter to work as a PSU for the 4090, it is worth the extra expense for a premium PSU!

Best Budget PSU for RTX 4090: Corsair RM1000x

Corsair RM1000x

Corsair RM1000x 80 PLUS Gold Fully Modular ATX 1000 Watt Power Supply

Wattage

1000W

Efficiency

Gold

Modularity

Fully-Modular

ATX 3.0

No

Pros
  • High quality & reliable
  • More affordable
Cons
  • Requires an adapter for 4090

If you need a more budget-friendly power supply for the 4090, we highly recommend Corsair’s reliable RM1000x model. Another ATX 2.0 unit, you’ll need an adapter to use it as a 4090 PSU, but for Gold-rated efficiency and 1000W of power at an affordable price point, it’s worth the extra hassle. Fully modular and packing 100% Japanese 105°C capacitors, the build quality on this budget option is impressively high. For a suitable PSU update to pair with your 4090, the RM1000x is a stellar option to save you money – even with an adapter factored in!

Best 1200W PSU for RTX 4090: Corsair 1200x Shift

Corsair 1200x Shift

Wattage

1200W

Efficiency

80+ Gold

Modular?

Fully Modular

Pros
  • Great wattage
  • Plenty of cable ports
Cons
  • Poorer build quality

If you are wanting the extra wattage that only a 1200W PSU can provide, then look no further than the Corsair 1200x Shift. Boasting 1200W of power and an 80+ Gold efficiency rating, this is a smooth and near-silent power supply for the RTX 4090. Though it is a little bulkier than other PSUs, it makes up for this with steller and stable power efficiency. For PSU overkill to match GPU overkill, the Corsair 1200x Shift is the best 1200W PSU for the 4090!

Best SFF PSU for RTX 4090: ASUS ROG Loki 1000W

ASUS ROG Loki 1000W

ASUS ROG Loki 1000W

Wattage

1000W

Efficiency

80+ Platinum

Modular?

Fully Modular

Pros
  • Small footprint
  • Platinum-rated efficiency
Cons
  • Premium pricing
  • Requires an adapter

If the 4090 is taking up all the space in your new SFX PC build, then the ASUS ROG Loki is a godsend. Packing 1000W into a tiny footprint, this brightly-colored and efficient PSU works great with the 4090 in a tiny case. With 80+ Platinum efficiency, this is also an energy-saving beast of a power supply unit with an LED screen on the side for easy monitoring. Though you will need a suitable adapter for using this PSU with the 4090, it is worth the extra hassle for those looking for maximum power with minimal space!

Why you should give your RTX 4090 some headroom

GPUs such as the RTX 4090 can occasionally spike in power requirements, same as other PC components. If a PSU cannot accommodate this higher demand, it can cause issues. This is why the actual wattage demands of a graphics processor are slightly higher than it actually needs, but we recommend a higher power supply regardless for extra longevity. Whenever you next decide to upgrade, the payoff of paying for a higher-power PSU will mean that you have less to throw out.

What kind of cable do I need for an RTX 4090 PSU?

The RTX 4090 comes with a new 12-volt high-power connector (shortened to 12vHPWR) with a more modern 16-pin connector design, therefore you will either need to buy a regular PSU and use an adapter to connect it, or you can purchase a recommended ATX 3.0 PSU with the new connectors as part of your cable kit.

Can I use the RTX 4090 in an SFX PC?

The major advantage of a custom-built PC is the ability to tailor components to your every desire. Though the RTX 4090 is quite a bulky PSU, it could be squeezed into an small-form PC build with some other downsized components. It is possible, but it won’t be roomy!

In Summary

In conclusion, when it comes to supplying your powerful RTX 4090 GPU, a PSU with at least 1000W is recommended, although you could get by with 850W too. The options above are all of the highest quality and are regularly used in our in-house builds for game-changing power efficiency.

It’s important to ensure that the PSU you select is compatible with the rest of your system and can support the power requirements of all of your components. Be sure to double check your preferred PSU against your planned build before you buy!

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