What PSU is best for RTX 4090?

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.

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 4090s 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.

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.

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.

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.

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.

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.

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.

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.

Still not sure which power supply is right for you? Why not try out our Power Supply Calculator. Just choose your components and we will calculate the best PSU for your specific pc setup.