The Nvidia GeForce RTX 3090 is the crowning achievement of its Ampere line, offering top-tier performance with power consumption to match. It’s not a GPU you can power with just any PSU, at least not if you want things to go smoothly. And that’s why you should invest in the best power supply for the RTX 3090 you can afford.

We’re focusing on higher-output power supplies here, starting at 850 watts and working up to 1000-watt power supplies with enough juice for heavy overlocking or RTX 3090 Tis. You can get by with less, but why skimp when buying such a beastly graphics card? But let’s stop wasting time; it’s time to get started.

Our Favorite PSUs for the RTX 3090

1. Corsair RM850x

Corsair’s RM850x is a great all-arounder, with its top-tier performance, decent noise profile, and competitive pricing. If you’re running your RTX 3090 at stock clocks, this is the best PSU for you. It’ll offer reliable, Gold-rated power without breaking the bank

Excellent transient response is an essential criterion for any PSU powering an RTX 30-series card like the RTX 3090. The RM850x performs well here, posting an average deviation of 1.18% on the 12-volt rail. It’s not quite the absolute best, but it’s not that far off the top spot. You won’t have any issues here, even when hammering your RTX 3090 with a heavy rendering load.

The RM850x’s load regulation is equally impressive, posting just 0.91% deviation on the 12-volt rails. It performs even better on the minor 3- and 5.5-volt rails, although those aren’t quite as crucial for the GPU. The ATX standard dictates a maximum ±5% deviation on the 12-volt rail, so the RM850x’s sub-1% results are excellent.

With such impressive transient response and load regulation numbers, you’d expect the RM850x to excel in ripple suppression, and you’d be right. Tom’s Hardware recorded 8.24 mV of ripple on the 12-volt rail, putting the RM850x at the top of their testing. Considering that the ATX spec allows for up to 120 mV of ripple on the 12-volt rail, the RM850x’s 8.24 mV is downright amazing.

Unfortunately, this excellent ripple suppression does come with a cost: in-cable capacitors on the main power cables. While these do a great job controlling ripple and reducing electrical stress on your components, they do make for thicker, slightly more unwieldy cables. We don’t think it’ll be a huge deal, but it’s something to bear in mind if you prefer using thin cables with a fully modular PSU.

Noise output is another slightly sticky area, at least compared to previous versions of the RM850x. The new magnetic levitation fan, combined with an aggressive fan curve, means that the RM850x emits around 30 dBA under load. It’s not terrible, but it’s not quite as good as the 19 dBA of the 2018 RM850x.

While both are real issues, we don’t think they’re significant enough to be deal-breakers. The Corsair RM850x’s performance, build quality, and 10-year warranty significantly outweigh the issues and make it the best power supply for 3090 in this wattage class.

2. Thermaltake Toughpower GF3 850 W

If you want a forward-looking 850-watt PSU that’ll last through the next couple of generations of graphics cards, then you’ll want an ATX 3.0- and PCIe 5.0-compatible unit. Thermaltake’s Toughpower GF3 850 W was one of the earliest of the kind on the market, and it’s still a compelling option when you consider its regular discounts.

Like any PSU worth its salt, the GF3 850 W has solid transient handling capabilities. It’s not the best in its class, but the 1.29% deviation Tom’s Hardware recorded is a solid enough result and won’t pose any issues with your RTX 3090.

The Thermaltake’s load regulation is solid but unremarkable, with a 1.16% deviation on the 12-volt rail. It can’t compete with the Corsair RM850x’s sub-1% results, but it’s not bad at all. The GF3 is more than adequate for most gaming rigs, even those with high-end hardware like RTX 3090s.

Ripple suppression is more impressive, although still not quite at the top of the pile. That said, 18.97 mV on the 12-volt rail is perfectly fine, considering the 120-mV limits set out in the ATX spec. It’s worth noting that the GF3 comes with capacitor-less cables, which increase ripple slightly but help with cable management. We think it’s a fair trade-off, especially when the difference between sub-10 mV ripple and 19 mV ripple is likely nonexistent in the real world.

Noise output is reasonable, with Tom’s Hardware measuring 29.81 dBA on average, so it’s fine but not necessarily quiet. That said, we’d be hard-pressed to imagine any of you finding the Thermaltake GF3 850 W’s noise output disagreeable in daily use.

If you’re after an 850-watt ATX 3.0 compatible PSU in the here and now, then the Thermaltake Toughpower GF3 is one of your best bets. It’s also widely available worldwide, which isn’t always true with many of its rivals. Add to that the keen pricing, and you have a solid PSU ready to power your rig for years to come.

3. Montech Titan Gold 1000 W

Montech may be new to the PSU game, but the Korean brand has made a splash with its Titan Gold products. These, including the 1000-watt unit here, offer solid ATX 3.0-compatible performance at prices competitive with older, non-ATX 3.0 units.

The Titan Gold 1000 W aces the standard ATX 2.2 transient response tests, posting an impressive 1.09% deviation on the 12-volt rail. It’s equally solid in ATX 3.0 testing, which hits the PSUs with extreme 120%, 160%, 180%, and 200% loads. Hardware Busters recorded a 4.68% deviation in the 180% load testing, which is within safe limits and means it’ll likely handle anything you can throw at it.

Admittedly, the Titan Gold 1000 W doesn’t look that impressive next to high-end ATX 3.0 PSUs like the Silverstone DA1000R Gold here. However, the Montech is around $60 cheaper, making it a much easier recommendation for the average builder. Besides, it’s still a perfectly safe performer here, considering your RTX 3090 won’t ever hit it this hard to begin with.

The Montech PSU’s load regulation is impressive, narrowing the gap to $250 rivals like the Silverstone. Hardware Busters measured a 1.05% deviation on the 12-volt rail to, which is more than adequate for a power supply. Yes, a measurement below 1% would be excellent, but it’s not the end of the world.

Ripple suppression is another area where the Titan Gold 1000 W impresses. It again comes close to the Silverstone DA1000R, posting 20.64 mV of ripple on the 12-volt rail. Not class-leading performance, but more than good enough considering the sub-$200 price.

Noise output is also reasonable, averaging 30.93 dBA in Hardware Busters’ testing at 115 V AC. Once again, it’s not the absolute best, but it’s perfectly adequate. It’ll certainly be quiet enough for all but the most sensitive users out there.

Since it’s an ATX 3.0 and PCIe 5.0-compatible PSU, you get a 12VHPWR cable in the box to power Nvidia’s latest RTX 40-series graphics cards. But you still get traditional 6+2 PCIe power cables in the box, so you’re fine to use this with an RTX 3090 in the meantime.

Overall, the Montech Titan Gold is a strong ATX 3.0 and PCIe 5.0-ready power supply perfect for your RTX 3090 and any future graphics cards you might buy. You may not need those features now, but its solid performance and Gold efficiency rating make it a good bet for a future-proof PSU.

4. FSP Hydro Ti Pro 1000 W

FSP’s Hydro Ti Pro 1000 W is more PSU than most people will ever need, but those of you seeking a bullet-proof, forward-looking power supply to pair with their RTX 3090 will find it here. It offers stunning electrical performance, Titanium-class efficiency, and full ATX 3.0 compatibility, making it ready for a decade’s worth of service, if not more.

How stunning, you ask? Let’s start with the transient response. Hardware Busters put the Hydro Ti Pro 1000 W through its tests and recorded a deviation of just 0.44% on the 12-volt rail. That’s some of the best transient handling you’ll see in a power supply, regardless of wattage.

It’s much the same case in the brutal ATX 3.0 tests, which hit the PSU with 120%, 146%, 180%, and 200% loads. The FSP keeps deviation to an impressive 2.31% at 180% load, the only PSU below 3% in Hardware Busters’ testing thus far. The FSP certainly backs its premium price up with its performance.

Load regulation is just as excellent, measuring 0.5% on the 12-volt rail. It’s one of the best PSUs in its class here, too, and it continues to justify its price. The only issue is that the minor 3.3- and 5-volt rails are less impressive by comparison, with Hardware Busters measuring 1.34% and 1.84% deviation, respectively. However, these rails aren’t as important, and we don’t think either is a huge issue.

The FSP doesn’t quite dominate as handily in ripple suppression tests. However, 19.74 mV of ripple on the 12-volt rail is excellent by all accounts and will hardly be an issue. Most of the FSP’s cables are capacitor-less, with only the 24-pin ATX cable featuring any filtering caps. So you shouldn’t have any issues with routing cables here.

FSP’s new 1000-watt monster also excels when it comes to noise output. Its highly efficient Titanium-class circuitry reduces heat buildup, allowing FSP to set a very relaxed fan curve. Hardware Busters measured just 12.65 dBA of noise output at 115 V AC, rising slightly to 14.69 dBA at 230 V AC. It’s not literally silent, but it might as well be: you won’t hear it over the rest of your system, that’s for sure.

One interesting feature that’s worth pointing out is the conformal coating on the Hydro Ti Pro 1000 W’s PCB. This coating protects the PCB from moisture, dust, and stains, and will help ensure it runs flawlessly for the length of its warranty (if not longer). FSP claims that it’s verified the PSU in environments up to 95% relative humidity, which is way worse than even the muggiest San Francisco day.

Overall, FSP’s Hydro Ti Pro 1000 W is the new king of the hill for 1000-watt power supplies. It’s overkill for most users, that’s for sure. However, RTX 3090 owners who want the best of the best and a PSU prepared for the rigors of future flagship GPUs from Nvidia or AMD will want to consider this.

5. Corsair SF750

Small form factor (SFF) builds and RTX 3090s aren’t exactly an obvious pairing, but it’s not an impossible one, as OptimumTech has proved. If you plan to follow in their footsteps, you’ll need a high-powered small PSU capable of fitting in any SFF case. Enter the Corsair SF750.

Yes, you can get more powerful compact PSUs, but most are in the larger SFX-L form factor, which isn’t as compatible. So we’ve opted for the SF750 as it’s a conventional SFX PSU that’ll fit in any compact case with room for a standard power supply. It will limit your power headroom somewhat, but you’re not likely to be doing any heavy overclocking in an SFF rig anyway. So it works out.

Like the Corsair RM850x, the SF750 excels at handling transients. The SF750 keeps transient-related deviation on the 12-volt rail down to an admirable 0.96%, besting many other high-quality SFX PSUs from the likes of Silverstone.

Load regulation is also top-shelf, with Tom’s Hardware measuring a minute 0.11% deviation on the 12-volt rail. Anything below 1% is already very impressive, but to keep the deviation at around 0.1% is truly outstanding. It gives full-sized PSUs a run for their money, and that’s not something you can say for most SFX PSUs.

The SF750 doesn’t manage to top the charts for ripple suppression as well, but it still performs excellently and won’t pose any issues. Tom’s Hardware measured 29.5 mV of ripple on the 12-volt rail, which isn’t good enough to put it at the top but more than good enough for an RTX 3090-based SFF system.

Unlike its full-size power supplies, Corsair opted to ship the SF750 without in-cable capacitors. This undoubtedly accounts for the slightly higher ripple numbers than is usual for high-end Corsair PSUs. Still, it has the benefit of making cable management much more straightforward in Mini-ITX cases.

Despite the smaller form factor dictating a 92 mm fan and more tightly-cramped components, the SF750 is still a quiet power supply, with an average noise output of only 26.2 dBA over its operating range. That’s an impressive result for an SFX power supply unit.

Overall, the Corsair SF750 is an excellent power supply for those crazy enough to build an RTX 3090-powered SFF rig. You’ll have to watch your power draw and lay off the overclocking, but there’s nothing to be concerned about beyond that.

What Power Supply Do I Need for an RTX 3090?

Nvidia recommends a 750-watt power supply for the RTX 3090, and an 850-watt unit for the RTX 3090 Ti. But as with the RTX 3080, opting for extra headroom is always helpful. Thus our recommendations focus on 850-watt units and go up to 1000-watt units for RTX 3090 Tis or heavily overclocked systems.

As usual, we recommend getting a rough estimate of your system’s power draw with a power supply calculator, just to see what you can and can’t get away with. Several are out there, but we usually use OuterVision’s PSU calculator. Any of the popular ones will work, though.

Simply choose all your components from the drop-down menu, and the calculator will provide a rough total wattage. It’ll even recommend a power supply if you need more suggestions.

Closing Thoughts

Choosing the best power supply for RTX 3090 is much the same task as for its smaller siblings: get a high-quality unit with enough power to feed it and the rest of your system. And it’s even more important here, given how pricey the RTX 3090 was and continues to be. The last thing you want to do is to fry a pricey GPU by using an underpowered or low-quality PSU.

If you want a solid 850-watt power supply and aren’t concerned about ATX 3.0 compatibility, Corsair’s RM850x is the easy choice here. But what if you want some future-proofing with ATX 3.0 and PCIe 5.0 compatibility? In that case, the Thermaltake Toughpower GF3 850 W or Montech Titan Gold 1000 W are the power supplies to go for.

Buying an RTX 3080 instead? Check out our list of the best power supplies for the RTX 3080 instead.