This is the maximum amount specified by the PCI Express standard for a x16 slot (PCIe 4.0 and 5.0 spec). If a graphics card requires more power, it will typically have additional power connectors ...

If you ever looked at a PCI to PCIe x16 adapter and wondered what’d happen ... to supply external power with even a low-end GT 1030 card – as the PCI slot cannot provide enough power ...

The common hardware interface in PCs, Macs and other computers for connecting peripheral devices such as storage drives and graphics cards. PCI Express (PCIe) was introduced in 2002 as "Third ...