The GeForce RTX 3090 is an exceptionally powerful graphics card, capable of producing stunning graphics with very high frame rates. They’re also very much in demand, and it’s only recently that they’ve started becoming easier to find in stores.
But as one of the best graphics cards you can buy right now, you need to factor in just how much power these beasts need to run. Many people looking to upgrade their PC to an RTX 3090 are going to have to upgrade their power supply to get it working.
With that in mind, let’s take a look at just how much power an RTX 3090 draws, along with tips on the minimum power supply you’re going to need for it to run.
How Many Watts Does An RTX 3090 Use?
The RTX 3090 is a power-hungry card that will draw somewhere between 355 and 365 watts when you’re gaming. As with any graphics card, that consumption drops considerably when the graphics card is idle, only needing around 18 watts to run.
At least, that’s true with a single monitor. It needs more power if you have a multi-monitor setup, closer to 26 watts. And if you’re using your PC to watch videos, the GPU will instead draw a slightly higher 32 watts.
It’s still low though – it’s only when the RTX 3090 needs to start rendering images live (for gaming or animation) that the consumption hits the heights of around 360 watts.
And while that’s the average recorded maximum, you need a little extra leeway to account for power spikes. Any component will have occasional power spikes that last less than a second, but could still cause your PSU to fail. The RTX 3090 has been recorded as having a spike as high as 464 watts, which is massive. (Source)
How Many Watts Does An RTX 3090 Use Per Hour?
Gaming with an RTX 3090 will use an average of 360 watt-hours per hour, which you can convert to 0.36 kilowatt-hours per hour. With the average gamer spending 8.5 hours playing a week, that means that the card will use an average of 3.06 kilowatt-hours per week.
There are a few caveats to that though. Firstly, that only factors in the gaming time. Most gaming PC users use their PC for other tasks too – whether that’s work, or watching videos online. The graphics card will use a lot less power for these times. If you spent 10 hours a week working on a single monitor, the graphics card would draw 0.18 kilowatt-hours.
The other main caveat is that this is only the power draw of the graphics card. Your PC has a lot more components, and while an RTX 3090 will be responsible for the majority of your power draw, it’s also likely that your processor will be high-end and will use a lot of power.
If you have a powerful processor alongside your RTX 3090 then don’t be surprised if your total PC draws closer to 0.7 kilowatt-hours per hour, or 6 kilowatt-hours per week.
It’s also worth mentioning that if your PC components are drawing 6 kilowatt-hours per week, that’s not how much power will actually be used. A power supply will always draw more than what is needed, because they aren’t perfectly efficient – some power is lost as heat generated by the PSU, and for the fan that keeps it cool enough to work.
Read more: How Many Watts Does A Gaming PC Use?
What Power Supply Do I Need For An RTX 3090?
The power supply you need for an RTX 3090 also depends on the rest of your system, but considering the likely high-end components you have, you’ll need a 750 watt PSU at least according to Nvidia. Realistically, an 850 watt PSU is a safer choice.
Bear in mind that a top-spec Intel Core i9 processor alone can draw around 200 watts, so just for the RTX 3090 and your processor you could have a power draw of around 550 watts. Add in the motherboard and then the rest of the components (which have minimal power draw generally) and you might be pushing the limits of a 750-watt power supply, especially when you get a spike.
So, the best thing you can do with an RTX 3090 is to aim big. 850 watts is the best minimum to realistically aim for, but if you can stretch to a 1000 watt PSU then that’s even better.
Bear in mind the efficiency rating too – you’ll definitely want at least an 80+ Gold for a power supply drawing this much power, otherwise, you’re wasting a lot of money.
Read more: Power Supply Ratings Explained
The Best Power Supply For An RTX 3090
The best power supply for an RTX 3090 will be one that balances a high power-rating with a strong efficiency. With most power supplies you can manage with an 80+ Bronze rating, but when you’re dealing with a high power draw you want something that’s more efficient, so aim for 80+ Gold or better.
This EVGA PSU is a great option, as it’s 80+ Gold rated for efficiency and can handle up to 1,000 watts of power draw, which is enough for the RTX 3090 in a premium build PC.
It’s semi-modular too, which means that apart from the standard 24-pin motherboard cable, every other wire is optional, so you don’t need to clutter your case with wires you won’t use. Expect any power supply at this level to be semi-modular or modular.
What RTX 3090 Power Cable Do I Need?
The power cable you need for your RTX 3090 depends on the model. Some of the cards are released with two 8-pin connectors, while others have three. You should always connect the full amount of cables for the connectors available.
There’s no real difference in performance if you get a 2 x 8-pin or 3 x 8-pin connector model. They will all still draw plenty of power to be able to perform at their maximum level.
RTX 3090 Power FAQs
While Nvidia recommends 750 watts as the minimum power supply for an RTX 3090, realistically you should aim for one that’s 850 watts or more, especially if you’re running one of the latest high-end processors. Otherwise, you risk a power spike causing your PSU to overload, which could damage it.
A 1,000 watt PSU is widely considered to be plenty for an RTX 3090 graphics card. Even with a top-end processor and gaming motherboard, you should have enough leeway to manage any power spikes, and it leaves you open to other upgrades in future too.
If you want to use your PC for crypto mining, an RTX 3090 will be sufficient. Bear in mind that the cost of using an everyday PC for crypto mining often outweighs the potential profit of any mined coin, and serious miners will buy dedicated setups using multiple graphics cards.