If you plug a high-speed GPU into a slot that is physically x16 but electrically x4, the card will run, but it will be restricted to slower data transfer rates.
The electrical width refers directly to the link width, which signifies how many bidirectional data lanes connect the motherboard slot directly to the CPU or chipset. Each lane consists of two pairs of wires: one pair to transmit data and one pair to receive. The Core Form Factors What is PCIe? Understanding PCIe Slots, Cards and Lanes
: This is the smallest PCIe slot, with one lane. It's often used for small peripherals like sound cards, network cards, and SSDs.
If your CPU supports PCIe 5.0, you can safely run a GPU at x8 without performance loss, freeing up lanes for multiple SSDs.
And next time you hear that click , you won’t just hear plastic and metal. You’ll hear the sound of 16 lanes of data, ready to fly.