One of the biggest questions surrounding Nvidia's GeForce RTX 40-series (Ada Lovelace) graphics cards is whether you need to upgrade your power supply. Nvidia has uploaded a new FAQ (opens in new tab) that sheds some light on Ada's power requirements for future adopters.
Consumers won't need to upgrade their power supplies if the capacity meets Nvidia's wattage recommendations. The GeForce RTX 4090 has a 450W TGP, meaning you need at least a 850W unit. The GeForce RTX 4080 12GB (285W) requires a 700W power supply while the GeForce RTX 4080 16GB (320W) will need a 750W unit.
So there you have it — as long as your power supply has enough juice and comes from a reputable vendor, you don't have to upgrade just yet. If yours don't comply with any requirements, you probably want to pick up one of the best power supplies.
For the GeForce RTX 40-series graphics card, Nvidia opted to use the new PCIe 5.0 power connector (12VHPWR) to reduce cable clutter and improve airflow inside the case. Some may be concerned about the 12VHPWR's fragile life cycle. However, the 30-cycle specification is the same standard for any PCIe or ATX connectors that have been with us for years, and it's unlikely that the typical user will plug and unplug the connector consistently.
The new ATX 3.0 power supplies come with the 12VHPWR connector. However, older units will have to rely on old-fashioned power adapters. According to Nvidia, GeForce RTX 40-series graphics cards will come with necessary power adapters, allowing existing ATX 2.0 power supplies to feed Ada with conventional 8-pin PCIe power connectors. These adapters can arrive with a three or four 8-pin to 16-pin designs.
There was a leaked email from a PCI-SIG member making rounds on the Internet about a potential overcurrent or overpower hazard with ATX 2.0 power supplies using 12VHPWR connectors. Obviously, the report caused a lot of panic among the enthusiast community.
However, some publications misinterpreted the PCI SIG's message: what PCI-SIG wanted to warn its members was that there was proof that some 12VHPWR connectors suffered from thermal variance under certain scenarios due to the components used in their production. It's likely that the components didn't conform with PCI SIG's requirements. Nvidia has confirmed that it was an isolated problem with a prototype connector from a specific vendor, and the supplier has since solved the issue.
With the 12VHPWR connector, four signal contacts are just sense wires. The signal contacts are not present with the power adapter, which is why the power adapters included with GeForce RTX 40-series graphics cards sport an active circuit that smartly picks up the power capacity based on the number of 8-pin PCIe connectors and report it to the graphics card. It is very useful since the minimum requirement for the GeForce RTX 4090 and RTX 4080 16GB is three 8-pin PCIe power connectors. So, for example, when the circuit detects four 8-pin PCIe power connectors, it permits the GeForce RTX 4090 to raise the power headroom for overclocking.
Whether to upgrade to an ATX 3.0 power supply depends on personal preference. It's not a big issue if you use a suitable adapter, but some may be against the usage of adapters with high amperage applications. However, it's understandable that not all users can or want to change their power supplies for a new one.