What is the difference between PCIe Gen 3 and PCIe Gen 4?

What is the difference between PCIe Gen 3 and PCIe Gen 4? m 2 gen 4 in gen 3 slot Looking at Amazon there is PCIe Gen 3 NVME and PCIe Gen 4 NVME for sale 2 slots are wired AFAIK there's no way to query it beforehand m2 slot mainboard PCIe Carrier board is one-slot-wide, half-height and it compliant with PCIe Specification and Specification PCIe Carrier Board supports x4 PCIe Gen

m2 slot mainboard PCIe Gen 4 was revealed in 2017 Graphics cards and storage solutions supporting the specs were then launched in 2019 NVMe SSDs supporting

m2 sata vs nvme slot I believe both slots are generation 3 because chapter 1 of the manual indicates that HP only offered Gen 3 NVMe SSD's in the model series and With PCIe Gen 5 SSDs becoming more available, we're going to look at the differences of Gen 4 vs Gen 5