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Best PSU for RTX 4090 in 2023 – our top 850W and 1000W picks

Need a power supply for an RTX 4090? You're in the right place.

Updated: Nov 16, 2023 10:26 am
Best PSU for RTX 4090 in 2023 – our top 850W and 1000W picks

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The RTX 4000 series has been with us for a while now, with the RTX 4090 the first to arrive on the scene. There has been an uplift in performance at the cost of power as well as power connectors, so with such a big requirement, we find the best power supply for RTX 4090. For starters, the RTX 4090 has a board power of 450W – a large increase in general over the previous offerings, but the same as the RTX 3090 Ti. This does mean the recommended power supply for the Founder’s Edition of the card is 850W.

Although some custom AIB cards will have a recommended PSU higher than the standard though so it can be higher. Such as the more powerful ROG Strix RTX 4090 recommends at least a 1000W power supply. With that in mind, we can start off by suggesting either the MSI MPG A1000G or ASUS ROG Thor 1000W Platinum II. There’s much more to talk about though, as we keep our selection up to date, let’s jump in.

Today’s best PSU deals

Best power supply for RTX 4090 in 2023

As discussed, power usage of your 4090 can vary depending on which model you do choose. Along with that, the new ATX 3.0 PSU standard changes the power connector. We’ve taken everything into account, so here are our top picks for the best RTX 4090 power supply.


Best RTX 4090 PSU


17 701 016 05




80 PLUS Gold



ATX 3.0


  • ATX 3.0
  • Fully-modular
  • 1000W
  • Efficient
  • Expensive

This is the MSI MPG A1000G and it is the perfect fit for anyone looking to power an RTX 4090 properly when it’s released. This power supply is from MSI, a well-known and well-respected PC peripheral manufacturer. The A1000G is 80 PLUS Gold certified, meaning it’s definitely got a few tricks up its sleeve when it comes to delivering power to your RTX 4090 efficiently. Speaking of power the A1000G comes with industrial-level protection, featuring OCP, OVP, OPP, OTP, SCP, and UVP.

MSI also has a 0 RPM fan mode, meaning your power supply will stay silent when it’s under a low load. The fan is also very quiet when it’s active, even at high loads. The A1000G features the new 12VHPWR connector meaning you can effortlessly power even the most demanding GPUs

ASUS ROG Thor 1000W Platinum II

Runner up RTX 4090 PSU

ASUS ROG Thor 1000W Platinum II

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80 PLUS Platinum



  • Attractive design
  • Fully-modular
  • 1000W
  • Very pricey

ASUS has been one of the best PC peripheral manufacturers for many years, although ASUS’s components can be pricey, they’re still well worth consideration. The Platinum II offers an 80 PLUS platinum certification carrying 1000W, making it the most efficient PSU on the list today, but also the most expensive. the Thor is built with 100% Japanese capacitors and other premium components to achieve this 80 Plus Platinum Certification.

To keep temperatures down, the Thor features ROG Thermal Solution. This is a new technology for ASUS using the power supply casing as a heatsink, paired with a 135mm fan to help keep the temperatures at bay. Although ATX 3.0 is not supported natively, the Thor does also come with a 12-pin PCIe cable (adapter) to offer easy connectivity to power your 4090.

Corsair RM850x

A good RTX 4090 PSU

Corsair RM850x

Corsair RM850x



80 Plus certification



Fully Modular

  • Fully modular for customization and clean building
  • Features maglev fan for the quietest and longest performance
  • Hybrid mode keeps the fan off until its needed
  • 10 year warranty to keep your PSU realiable and long lasting
  • Can be a more expensive option

One good option for powering your RTX 4090 is the Corsair RM850x. One of the most popular choices is a versatile and efficient model. It has the Gold 80 PLUS certification, an average but good specification to get. As it still saves you a bit of money with efficiency but doesn’t come with the more premium features of higher models.

It is also a fully modular supply. This means all of the cables are not permanently attached. So you get the choice of personalization, as well as keeping your cable mess down. Helping a tonne with those of you that aren’t very keen on cable management.

This PSU does not have the new 12VHPWR connector, unfortunately, which means you’re going to have to use the octopus connector that comes with most ATX 3.0 power supplies.

EVGA 850 B5

Best Budget PSU

EVGA 850 B5 850 W

EVGA 850 B5 850 W


850 W


80+ Bronze



Form factor

Standard ATX

  • Great budget option with reliability and a good brand
  • Modularity allows for good clean building for a good price
  • Only Bronze efficiency which can mean higher running costs

If you spent all of your money on the GPU, then you may choose a bit of a cheaper option for the power supply. You still want something reliable as it is responsible for the whole system and so it going wrong would mean disaster.

So EVGA is a great choice as it is a well-known brand with good quality products and so it is a cheaper option but with good history behind it. So it is a good pick, although if you want some more power you may need something more. As there won’t be much headroom with just 850W.

Especially with a bronze power rating, it means that it is a bit more inefficient than other picks. In a cost-saving measure to buy the product, it will cost a bit more for you to run it. As the inefficiency in the conversion will require more to run it.

Seasonic Prime PX-1000

Most efficient power supply

Seasonic PRIME PX-1000

Seasonic PRIME PX 1000



80 Plus certification



Fully modular

  • Incredible build quality
  • Silent operation
  • Full power at 46°C
  • 12-year warranty
  • Very expensive

Now when it comes to picking out an efficient power supply, Seasonic is the supplier to find. With a high-quality build and long-lasting warranty, it means it should last you quite some time.

And that comes with very high efficiency. With a titanium rating, it should give you a much lower electricity bill when running your system. Which can add up over time and that may be worth the initial higher cost. So you’ll also get the ability to have a quietly running supply.

How we choose

best PSU

When trying to pick out the best PSU there are multiple factors to consider in the selection process. With so many options, there is a lot to think about. Going off of reviews and years of experience, we know what to look out for and what makes up a good PSU.

We make sure the wattage provided will be enough for the use case. As well as ensuring it has a good efficiency score with a quality build. As it is going to be running you want to keep the costs down long-term. Also ensuring not too cheap out on it as it does hold the life of the rest of your components in it so it is best to make sure it is suitable and works well.

Best power supply for RTX 4090 buying tips

Choosing a new power supply comes with plenty of considerations. There are a lot of specifications out there on the PSUs that may not be of equal value. And so we explain what are the key features to look out for when selecting the best power supply for your RTX 4090.


ROG Strix RTX 4090 28

One of the primary features of a power supply will be how much power it can in fact provide. As its primary use, it needs to have enough energy to split across all your computer components. So you have to consider how much you will need to have enough for your entire system, even if the GPU is the primary biggest user.

To find out how much wattage you need, add up all the power ratings of your build. Either by using the specifications or tools online that can do it for you. Although GPU manufacturers also suggest the system power to use for your build with that card in it. So there are a few methods to consider when looking for that information.

Now the RTX 4090 has a board power of 450W. And Nvidia for its Founder’s Edition card says you need a minimum system power of 850W. That is when it’s paired with a Ryzen 9 5900X, so your overall power may vary. And in fact, different models suggest a different amount, such as the ROG Strix OC suggesting the full 1000W.

So it’s a good idea to have some spare on top of the required power. This is so your system doesn’t unexpectedly shut down or throttle your performance. Which can come from the power spike drawn from random loads and such.

Cables and modularity

ROG Strix RTX 4090 7

Nobody likes cable management, and that’s one of the reasons modular power supplies are so great. With a modular power supply, you only need to connect what you need. You don’t have to worry about birds nesting that useless abundance of SATA and MOLEX connectors at the bottom of your case.

Fully modular PSUs have no cables hard wired to the unit, every single cable, including the 24-pin power and CPU power connectors, is modular. It also happens that fully modular power supplies are usually the most expensive, with the most connectivity available.

Semi-modular power supplies are a hybrid between fully modular and non-modular, Semi-modular PSUs usually have 24-pin power and 8-pin CPU power hard-wired into the unit. Not usually a problem, since in 99% of cases you need both of those cables. So you could possibly save a buck or two if you opt for a semi-modular PSU over a modular one.

Then there’s the non-modular, the lowest of the low. These little bundles of inconvenience are usually ketchup and mustard-colored eyesores. They are inexpensive, but if you don’t have a large case with good cable management options, they can turn a great build sour. Non-modular gets the job done, but at what cost?


PSU 80 PLUS Certification

Power supplies have one job, and that’s to supply power to the PC, who knew? If you know anything about electricity and electrical circuits, it’s that they can be incredibly inefficient. So power supplies have had to be designed to waste as little energy as possible, and thus the efficiency rating was born.

The official certification is the 80 PLUS certification. This can quickly tell you how efficient your power supply is. Obviously, the more efficient the power supply is, the more expensive it will be, but it may help you save money on power in the long run. Especially if you keep a beefy rig running 24/7.

Power supplies have an efficiency rating based on colors, there are white, bronze, silver, gold, platinum, and titanium. As you can imagine, white is the worst and titanium is the best. We don’t know why it has this rating system, we’d choose platinum over titanium any day of the week.

Now let’s see the numbers. the power efficiency ranges from 80 PLUS white, that is 80% above 20% loads on 115V non-redundant and 230V non-redundant, but no spec for 230 V internal redundant. All the way up to Titanium which has at least 90% efficiency across all loads. This obviously does increase the cost of the PSU but will be better at power management.

ATX 3.0 12VHPWR connector

GIGABYTE PCIE Gen 5 16 pin connector

ATX 3.0 is a new power supply standard, updated for the increasing power demands in the PC gaming industry. The main reasons for updating to this standard are the increased efficiency on offer since energy prices are soaring and the new 12VHPWR connector.

The RTX 4090 is a chonker of a GPU and requires 450W to keep going steady, some AIBs even allow you to unlock that power limit and crank it above 500W that’s insane!

And that’s exactly the reason we need a new connector, currently, PCIe ATX connectors can only deliver around 150W from the PSU to the source. The new 12VHPWR connector cranks those ATX numbers up to 11, with the potential to deliver up to 600W continuously and up to 1200W power excursions.

If you want to find out more, take a look at our ATX 3.0 PSU article.

Best PSU for RTX 4090 FAQs

What is the RTX 4090 board power?

The RTX 4090 has a total board power of 450W. Although some custom AIBs will require even more even reaching 500W or more.

What PSU do I need for RTX 4090?

The Founder’s Edition and some custom models ask for an 850W power supply. But with a more powerful rest of components, and other custom cards like the ROG Strix recommend a power supply rated for 1000W.

How much power does RTX 4090 need?

The RTX 4090 has a power rating of 450 W. Whilst some of the custom AIBs might require about 500W. This puts the required power supply rating to 850 W, or 1000 W to be on the safe side and alow for bigger ratings.

What is the best power supply for the RTX 4090?

When it comes to powering your beast of a GPU there is some power needed and some new standards to go by. So for the best PSU for the RTX 4090, the MSI MPG A1000G is a good choice. The ASUS ROG Thor Platinum is a good choice for efficiency. Whilst an RM850X is a good budget option, Corsair offers a 16-pin adapter that may fair better.

Is 1000 watts enough for 4090?

Yes, 1000 W is plenty for the RTX 4090. It has a suggested supply of 850 W, but some custom models will ask for a larger supply to be enough. Therefore 1 GW should be enough to cover all of them.

Final word

No matter what power supply for RTX 4090 you choose from this list, you’ll have a very capable power supply capable of fully supporting the new 4090 GPU. A chonker in its own right. Some comforts are nice to have, like a fully modular PSU and the option of a fan silent mode. But that’s not all necessary when it comes to power supplies. If you’re looking to save a few dollars, you can skip on some of these features.

At the end of the day, the two most important things are safety and efficiency, so if you can pick up a PSU that hit those two marks, you and your RTX 4090 will be just fine. Just make sure you keep up the payments on the small loan you took out to buy the 4090 in the first place.

With a background in engineering and PC gaming, Seb is a staff writer with a focus on GPU, storage, and power supplies. Also one of tech supports in the office he likes helping and solving problems.

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