Question Does a GPU prioritise power draw from the PSU or PCIe?

[Tafjeera]

Hi all

A thoughtful question came to mind when looking to buy a case with a GPU riser cable rated at 45W.

If I buy a graphics card that can be powered by your PSU, will it first pull all 75W from the PCIe slot, then the remainder from the PSU?

Or, will it pull what it can from the PSU, and the remainder from the PCIe slot (if it requires more)?

Essentially, I've read stories where 75W graphics cards running on PCIe only have burnt out riser cables that can't carry the full 75W, so I was looking at cards that are PSU powered.

Thanks in advance.

 

[Newtonius]

As long as the card has power connectors it should draw most of it's power via the PSU's 12v rails. It does draw some power from the PCIe slot but not more than the riser is rated for since it's power will be coming from a dedicated source. If the riser is rated for 45W then it will draw the power from the PSU mostly and whatever else it can from the riser.

 

[Tafjeera]

That's great to hear.

This was the one last bit of info I needed to go with a tiny ITX build, so thanks a million!