PCIe vs PCIe : What's the difference?

Yes, a PCIe x4 card will function in a PCIe x16 slot The slot will simply use 4 of the 16 lanes available, and the card will work properly

PCIe x4: These have four PCIe lanes, and they also can fit into a x16 slot Often used for single NVMe SSD expansion cards, they are

can you put ddr3 in ddr4 slot All PCIe slots are backward compatible, so if you have an older-generation card, it will work just fine without any trouble This way you can

can slot machines be adjusted There's been talk that some PCIe slots on new motherboards will (The support may only be extended to ordinary PCIe x16 expansion slots