What is the order of power intake across a GPU's power connectors?

[Coldblackice]

On an Nvidia/EVGA 3080/3090 FTW3 GPU, there are three 8-pin PCIe power connectors. How does the "ordering" of power draw work across its 3x power ports (+ its PCIe slot)?

For example, if a 3080 FTW3 suddenly needed 450W of power, how or in what order would that be drawn: would it grab as much power as it can get from one power source before moving onto the next, e.g.:

• 75W from PCIe slot (..75W total)
• -> 150W from 8-pin #1 (..225W total)
• -> 150W from 8-pin #2 (..375W total)
• -> remaining 75W from 8-pin #3 (..450W)

..? Or does the GPU draw power through all the ports in parallel? What happens if one port can't supply power equally as the other two?

As an example: if you have two 8-pin PCIe power cables + one 6-pin -- given 6-pin cables will only have 75W max drawn over them -- what would happen as far as power draw? Would it matter which port the 6-pin cable was plugged into? How would the GPU respond in a case like this, or if the 6-pin cable was alternated between ports 1-3?

[HotdropHeinz]

14 minutes ago, Coldblackice said:

Or does the GPU draw power through all the ports in parallel?

I'm not sure about the power usage of the PCIE slot but all powercables are just in parallel. It takes pretty much the same amount over each connector.

PCI-E power management probably is handled by the cards driver primarily. Additionally the board probably limits the supply over PCI-E to max 75W.

[Ankerson]

3 hours ago, Coldblackice said:

On an Nvidia/EVGA 3080/3090 FTW3 GPU, there are three 8-pin PCIe power connectors. How does the "ordering" of power draw work across its 3x power ports (+ its PCIe slot)?

For example, if a 3080 FTW3 suddenly needed 450W of power, how or in what order would that be drawn: would it grab as much power as it can get from one power source before moving onto the next, e.g.:

• 75W from PCIe slot (..75W total)
• -> 150W from 8-pin #1 (..225W total)
• -> 150W from 8-pin #2 (..375W total)
• -> remaining 75W from 8-pin #3 (..450W)

..? Or does the GPU draw power through all the ports in parallel? What happens if one port can't supply power equally as the other two?

As an example: if you have two 8-pin PCIe power cables + one 6-pin -- given 6-pin cables will only have 75W max drawn over them -- what would happen as far as power draw? Would it matter which port the 6-pin cable was plugged into? How would the GPU respond in a case like this, or if the 6-pin cable was alternated between ports 1-3?

 

I posted in the other forum.

 

To clarify the card will not boot without all 3x 8 Pins connected, I tried it myself to confirm.

 

When the card starts up it hits all 3x 8 pin connections at the same time in microseconds, zero to 450W in an instant. And from what I can tell it pulls almost all of it from the 3x 8 Pin connections. Saw 468W power draw from the 3x 8 Pin on my card.

 

#8, #9 and #10 are the PCIe connections. 12A+12A+15A=39A ...... 39A X 12 = 468W

 

 

Your RMX 850 has the correct connections for the 3080 FTW3 Ultra.

 

It comes with 3x Daisy Chained 6+2 PCIe cables for a total of 6x 6+2 connections.

 

@jonnyGURU