Today, we're going to find the best Power Supply Unit (PSU) for the NVIDIA GeForce RTX 4090 from the considerably broad CORSAIR PSU selection. Given the huge power requirements and high prices of modern graphics cards (GPUs), a high-quality, power-efficient PSU is highly recommended.
Before we get too far into it, you should know that there are a few bare minimums for your system:
RTX 4090 SYSTEM REQUIREMENTS
- PCIE 4.0 X 16 SLOT (For best performance)
- 850W Power supply or greater.
- MIN 3 x 8 pin PCIE Connectors + Adapter provided / 450W or greater PCIE GEN 5 power cable.
So, first we're going to go over what you need to keep in mind when choosing a PSU for the RTX 4090, starting with the power requirements of the different RTX 4090 models that are available.
RTX 4090 POWER REQUIREMENTS
It's vital to note that not all RTX 4090 GPUs are the same. Importantly here, they don't have the same power requirements. Depending on the specific model, they can have different power consumption levels, meaning that you must know the power consumption of your specific RTX 4090 so you can choose a suitable PSU. Additionally, momentary power spikes are not uncommon, so it's best to over-spec your PSU.
So, here's a table of a few RTX 490s and their TDPs (Thermal Design Power) as well as their recommended minimum PSU wattages.
You should note that this is not an exhaustive list. If your GPU is not listed make sure to check. You'll find the PSU wattage recommendation and the TDP in the user manual or on the manufacturer's website.
| Model | TDP (Thermal Design Power) | Minimum recommended PSU |
|---|---|---|
| NVIDIA GeForce RTX 4090 (Founder's Edition) | 450W | 850W |
| Zotac NVIDIA GeForce RTX 4090 24GB Trinity OC | 450W | 1000W |
| ASUS NVIDIA GeForce RTX 4090 24GB TUF Gaming | 450W | 850W |
| MSI NVIDIA GeForce RTX 4090 24GB SUPRIM X | 320W | 850W |
| Gigabyte AORUS NVIDIA GeForce RTX 4090 24GB MASTER | 450W | 1000W |
| ASUS NVIDIA GeForce RTX 4090 24GB ROG Strix OC | 450W | 1000W |
| MSI NVIDIA GeForce RTX 4090 24GB VENTUS 3X 24G OC | 450W | 850W |
| Gigabyte NVIDIA GeForce RTX 4090 24GB GAMING OC | 450W | 1000W |
From this list, you can see that the recommended PSU and TDP varies, with some quoting TDPs as low as 320W and 850W PSUs. Despite this, we're going to focus on 1000W PSUs today, as it gives a bit more breathing room to deal with transient spikes and allows for adding more components to the system before having to upgrade the power supply. We'll also include an 850W option, for those who don't want any extra capacity.
BEST FULLY MODULAR ATX PSU FOR RTX 4090: CORSAIR RM1000x SHIFT
Your best fully modular PSU option is the CORSAIR RM1000x SHIFT. Not only is it fully modular, but the cables connect to the side instead of the end. This makes for far easier and neater cable management. It also features a Zero-RPM fan mode, so the fan won't spin unless it needs to, resulting in a quieter build when under low power draws. It's also available in a 1,200W variant, if your system is particularly extensive.
CORSAIR RM1000x SHIFT SPECS
For the technologically-astute amongst you, here's the specs of the CORSAIR RM1000X SHIFT, with the power table and cable configuration. We'll do the same for the other PSUs in this page.
| Rail | +3.3V | +5V | +12V | +5Vsb | |||
|---|---|---|---|---|---|---|---|
| Max current | 20A | 20A | 83.3A | 3.0A | |||
| Max combined wattage | 150W | 1000W | 15W | ||||
| 1000W | |||||||
| Cable type | Description | Length | Cable Quantity |
| Flat | ATX CABLE 24-PIN (24) | 610mm ± 10mm | 1 |
| Flat | EPS/ATX12V CABLE 8-PIN (4+4) | 650mm ± 10mm | 2 |
| Flat | 12VHPWR Cable (12+4) | 650mm ± 10mm | 1 |
| Flat | PCIe CABLE 8-PIN (6+2) x2 | 750mm ± 10mm | 2 |
| Flat | PCIe CABLE 8-PIN (6+2) | 650mm ± 10mm | 3 |
| Flat | SATA CABLE (4 SATA) | 800mm ± 10mm | 4 |
| Flat | PATA CABLE (4-PIN) | 750mm ± 10mm | 2 |
BEST FULLY MODULAR SFX PSU FOR RTX 4090: CORSAIR SF1000L
Despite the gargantuan size of the RTX 4090, you can still fit one into small form factor builds, so long as the case you're using has enough clearance for it. In fact, our 2000D AIRFLOW SFF case can fit several RTX 4090 models (as long as the specific RTX 4090 doesn't exceed 365mm.) This means that we had to include a SFX PSU here. and we've chosen the CORSAIR SF1000L.
CORSAIR SF1000L SPECS
| Rail | +3.3V | +5V | +12V | +5Vsb | |||
|---|---|---|---|---|---|---|---|
| Max current | 20A | 20A | 83.3A | 3.0A | |||
| Max combined wattage | 150W | 1000W | 15W | ||||
| 1000W | |||||||
| Cable type | Description | Length | Cable Quantity |
|---|---|---|---|
| Flat | ATX CABLE 24-PIN (24) | 300mm ± 10mm | 1 |
| Flat | EPS/ATX12V CABLE 8-PIN (4+4) | 400mm ± 10mm | 2 |
| Flat | 12VHPWR Cable (12+4) | 400mm ± 10mm | 1 |
| Flat | PCIe CABLE 8-PIN (6+2) x2 | 500mm ± 10mm | 1 |
| Flat | PCIe CABLE 8-PIN (6+2) | 400mm ± 10mm | 3 |
| Flat | SATA CABLE (4 SATA - Right Angled) | 445mm ± 10mm | 1 |
| Flat | PATA CABLE (4-PIN) | 750mm ± 10mm | 1 |
BEST ULTRA-QUIET ATX PSU FOR RTX 4090: CORSAIR HX1000i
For many PC enthusiasts, having a quiet build is of paramount importance, and if you want near silent operation, even when under load, the CORSAIR HX1000i is the best option. Like the RM1000x SHIFT and the SF1000L, it has a zero-RPM fan mode, providing genuinely silent operation at low loads. Unlike the other PSUs, however, it features a magnetic levitation fan. This means that there's almost no contact between the fan and the bearing, which results in near-zero friction. Less friction = higher speeds and lower noise.
CORSAIR HX1000i SPECS
| Rail | +3.3V | +5V | +12V | +5Vsb | |||
|---|---|---|---|---|---|---|---|
| Max current | 25A | 25A | 83.3A | 3.0A | |||
| Max combined wattage | 150W | 999.6W | 15W | ||||
| 1000W | |||||||
| Cable type | Description | Length | Cable Quantity |
|---|---|---|---|
| Flat (Sleeved) | ATX CABLE 24-PIN (24) | 610mm ± 10mm | 1 |
| Flat | EPS/ATX12V CABLE 8-PIN (4+4) | 650mm ± 10mm | 2 |
| Flat | 12VHPWR Cable (12+4) | 650mm ± 10mm | 1 |
| Flat | PCIe CABLE 8-PIN (6+2) x2 | 775mm ± 10mm | 2 |
| Flat | SATA CABLE (4 SATA) | 800mm ± 10mm | 2 |
| Flat | PATA CABLE (4-PIN) | 750mm ± 10mm | 2 |
| Round | USB Type-C to 10-1 Pin | 525mm | 1 |
BEST 850W PSU FOR RTX 4090: CORSAIR RM850E
Not everyone feels the need to have additional power capacity for future upgrades. This makes sense as it's a way to keep costs lower. Additionally, lower capacity PSUs are often smaller in size, creating more room for storage drives, as many cases have the mounts for these adjacent to the PSU. Smaller PSUs also make cable management that much easier. So, if this sounds good to you, then we recommend the CORSAIR RM850e fully modular PSU.
| Rail | +3.3V | +5V | +12V | +5Vsb | |||
|---|---|---|---|---|---|---|---|
| Max current | 20A | 20A | 70.8A | 3.0A | |||
| Max combined wattage | 150W | 850W | 15W | ||||
| 850W | |||||||
| Cable type | Description | Length | Cable Quantity |
|---|---|---|---|
| Flat (Sleeved) | ATX CABLE 24-PIN (24) | 610mm ± 10mm | 1 |
| Flat | EPS/ATX12V CABLE 8-PIN (4+4) | 650mm ± 10mm | 2 |
| Flat | 12VHPWR Cable (12+4) | 650mm ± 10mm | 1 |
| Flat | PCIe 8-Pin (6+2) | 650mm ± 10mm | 1 |
| Flat | PCIe CABLE 8-PIN (6+2) x2 | 750mm ± 10mm | 2 |
| Flat | SATA CABLE (3 SATA) | 800mm ± 10mm | 2 |
| Flat | SATA CABLE (4 SATA) Right Angle | 800mm ± 10mm | 1 |
| Flat | PATA CABLE (4-PIN) | 750mm ± 10mm | 2 |
RTX 4090 PSU FAQS
So, those are our picks for the best PSU for the RTX 4090. However, now we're going to take a moment to answer some of the more common queries surrounding this GPU, our PSUs, and more.
How long is the warranty on a CORSAIR PSU?
All our PSUs come with a minimum of a 3-year warranty, with many holding 10-year warranties. You can find the warranty for each specific PSU on our support site.
What power cable does the RTX 4090 use?
Typically, RTX 4090 GPUs come with an adapter cable that takes three or four 8-pin connectors and combined them to the 12VHPWR 16-pin socket on the GPU itself. However, this is only necessary if you're using a PSU that isn't ATX 3.0 certified. All the PSUs we've recommended here have that certification, and thus include the 12VHPWR cable in the box, so you won't need to use the adapter that came with the GPU.
Are there still issues with the 12VHPWR connector?
Following the release of the 12VHPWR standard, there were some incidences of the connector melting, due to it not being fully-seated when connected. This is avoidable, just make sure the cable is fully connected at both ends, and avoid bending the connector during the cable management process. Our PCIe 5.0 12VHPWR GPU Power Bridge can help with that, allowing for neater cable management, and a lower likelihood of the cable being bent too much. (Just check it will work with your specific RTX 4090.)
What does the "80 Plus" symbol mean?
This is an industry-standard way ofvalidating the efficiency of a power supply. All our PSUs, including those on this list, carry a certification of Gold or higher.
Are all PSU cables compatible with all PSUs?
No. there are different standards and connector types at play here. This means you have to be very careful. Check out our compatibility matrix to make sure. Plugging the wrong type of cable into your PSU, or any other component in your system can have disastrous consequences.
