PCIe Gen5 power connector is compatible with GeForce RTX 30 Founders Edition

PCIe Gen5 slot fits Molex MicroFit 3.0 used by NVIDIA RTX 30 Founders Edition

Over the past few months there have been numerous reports of next-gen GPUs with next-gen power connectors. At the same time, power supply manufacturers are beginning to introduce new products equipped with such connectors

PCIe Gen5 cable and ASUS Thor II 1000W Platinum power supply, source: ASUS

A few months ago, ASUS announced the Thor PSU series (pictured above) announced as Gen5 ready. The ASUS ROG Thor 1000W Platinum II PSU reportedly comes with a 12-pin cable that can supply up to 600W of power, which was actually the first power supply to feature this connector.

According to Andreas Schilling of HardwareLuxx, this connector is actually compatible with the NVIDIA RTX 30 Founders Edition 12-pin cable, also known as “Molex MicroFit 3.0 Dual Row (12 circuits)”. Not only is the cable physically identical, but it also delivers the same amount of power. This basically means that NVIDIA implemented the next-gen connector almost over a year before the standard was even introduced.

ASUS THOR PSU PCIe Gen5 cable attached to GeForce RTX 30 FE card, Source: Andreas Schilling

The difference between PCIe Gen5 12 pin, 12+4 pin and 16 pin

More recently, ASUS announced a new generation of power supplies codenamed Loki. The images show that Loki PSUs would be the first to feature a full implementation of the PCIe Gen5 connector, which is 12+4 pins. According to Igor’sLAB, these 4 extra pins are sideband signal carriers to sense how much power to supply to the GPU. This complete implementation of the connector is known as the “12VHPWR High Power Connector (H+)”.

There is some naming difference here though, as some call it “12+4 pin” while others just call it a 16 pin. The latter could refer to the 16-pin MicroFit cable, which has not yet been used by any card and would likely be incompatible with future GPUs. Therefore, it should be correct to call a 12+4 pin cable as a 16 pin cable.

PCIe Gen5 16-pin power cable, Source: Igor’sLAB

So what exactly does this mean? This means that Geforce RTX 30 Founders Edition will work with PCIe Gen5 slots, simply because they don’t need more than 450W. This is a limit imposed by the S3 signal (SENSE0), if it is not grounded, the power supply will not supply 600W but up to 450W. In an example of the ASUS Thor PSU and their 600W request for a 12-pin cable, this means the SENSE0 signal must be grounded internally.

Meanwhile, the S1 (CARD_PWR_STABLE) and S2 (CARD_CBL_PRES) signals should ensure that the graphics card is properly connected and the power budget has been properly negotiated. The fourth signal (S4) is not defined by the latest PCI-SIG specifications.

ASUS Loki PSU with 12+4 cable, Source: ASUS

GeForce RTX 3090 Ti and 600W+ GPU

The Gen5 connector is rated up to 9A at 12V, which means a maximum current of 648W. However, the official specifications define a maximum of 600W. This means that next-gen GPUs may end up with one connector instead of a triple 12-pin configuration. Hopefully the AMD RDNA3/NVIDIA Lovelace GPU generation won’t require anything more powerful.

Earlier rumors suggested that NVIDIA’s next flagship GPU, known as the RTX 3090 Ti, could be the first card to use this new PCIe Gen5 slot. So far, there’s only been a teaser from EVGA showing off the new Kingpin model which clearly lacks a typical 8-pin connector configuration.

Maximum theoretical power consumption of a graphics card
video cardz PCIe slot 6 pins 8 pins 12 (+4) pins total power
Entry level 75W
75W 1x 75W
Midrange 75W 1x 150W
75W 2x 75W
Top of the line 75W 1x 75W 1x 150W
75W 2x 150W
Passionate 75W 1x 75W 2x 150W
75W 3x 150W
Next generation flagship 75W 1x 600W
75W 2x 600W

Source: HardwareLuxx



Alan A. Seibert