Nvidia explains PSU requirements for GeForce RTX 40 series GPU

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With a power usage of up to 450 watts, the Lovelace generation seems to be get a significant increase in power consumption, and thus power supply.

NVIDIA adress the power requirements for power supplied in a blog post. First, you're not going to need a new power supply if you meet the recommended wattage. Each graphics card has a power adapter to ensure compatibility with existing power supplies. NVIDIA have precisely tested the power adapters across a wide range of conditions. Answers to common questions are below, including PSU wattage recommendations for each card, the lifetime number of reconnections, and more.

Very interesting to observe is that the new 12VHPWR power connector adapter cable has four PCIe PEG connector, yet you can connect three of them, and the card will still work. 

Common Questions about RTX 40 Series Power Supply Compatibility

Do I need to upgrade my PSU for the RTX 40 Series?

The RTX 40 Series doesn’t require a new power supply if you already meet the PSU wattage recommendations. The RTX 4090 TGP is 450 W and the minimum recommended PSU is 850 W. The 4080 16GB TGP is 320 W with a minimum recommended power supply of 750W, and the minimum recommended power supply for the 4080 12GB is 700W.

How do GeForce RTX 4090 and 4080 power requirements compare to last generation?

The power requirements have stayed the same or reduced while delivering substantially more performance. RTX 4090 draws the same power as RTX 3090 Ti, the RTX 4080 16GB draws 30W less than RTX 3080 Ti, and the RTX 4080 12GB draws 65W less power than RTX 3080 12GB.

Do the RTX 40 Series cards require a new type of power connector or a new power cable?

No. The RTX 40 Series cards come with power adapters that allow you to use existing power supplies with existing 8-pin PCIe connectors. The RTX 40 Series cards can also use the PCIe Gen5 power connector which allows you to power the graphics card with a single cable.

If the RTX 40 Series cards can use the existing connectors and power supplies, then why change to a new connector standard?

The PCIe Gen5 power connector is the new standard for PCIe add-in-card power. The standard allows you to power the graphics card with a single cable, which simplifies cable routing and improves airflow inside the chassis, among other benefits.

PCI-SIG warned of potential overcurrent/overpower risk with 12VHPWR connectors using non-ATX 3.0 PSU & Gen 5 adapter plugs. Why did PCI-SIG issue the warning and how does this affect NVIDIA’s new products?

It does not affect NVIDIA’s new products. During early development and testing we identified a potential issue with a prototype connector manufactured from a sole supplier. As a PCI-SIG member, we informed the supplier, asked them to fix it (which they did), and shared our findings to help suppliers who are implementing the new standard. The PCI-SIG was passing along those learnings to other suppliers.

Why is there only a 30 cycle lifetime on these new PCIe Gen 5 connectors?

The 30 cycle spec is the same as it’s been for the last 20+ years on existing PCIe/ATX 8pin connectors, and has not changed with the PCIe Gen5 connectors or power adapters.

Are the RTX 40 Series Adapters “smart” enough to interface with a ATX 2.0 PSU and appropriately regulate the power to the GPU?

Yes. The adapter has active circuits inside that translate the 8-pin plug status to the correct sideband signals according to the PCIe Gen 5 (ATX 3.0) spec.

What’s a ‘smart’ power adapter?

The adapter has an active circuit that detects and reports the power capacity to the graphics card based on the number of 8-pin connectors plugged in. This enables the RTX 4090 to increase the power headroom for overclocking when 4x 8-pin connectors are used versus 3x 8-pin connectors.

If I bend the RTX 40 Series adapter will it cause issues with the connection between my PSU and GPU?

The adapter has been proven to work in a wide variety of conditions. Please follow our compatibility diagram: plan a minimum of 1.4” or 36mm clearance above the top of the graphics card for cable bend and airflow clearance.

Should I be concerned if my PSU only has one power rail available to connect my graphics card (i.e. only have 1 power connection available)?

Please connect the original power supply output connectors and cables directly to the included power adapter. Power supplies typically only supply up to 2x 8pin PCIe connectors per output cable. RTX 4090 and RTX 4080 16GB require at least 3x 8pin PCIe connectors or a 450W or greater PCIe Gen 5 connector.

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