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

m 2 gen 4 in gen 3 slot   Dan m2 nvme slot

First of all, I know that a PCIe 4 SSD NVMe will be running at gen 3 speeds and bottlenecked by the PCIe 3 slot But I'm wondering if there are

The UD85 makes it easy to upgrade from PCIe Gen 3 to Gen 4 It's also backwards-compatible with Gen 3 for greater flexibility across systems And, its slot supports PCIe Gen 4 x4 SSDs, while the right slot supports only PCIe Gen 3 x4 SSDs or SATA SSDs 0

zeus png slot Most NVMe SSDs utilize the x4 connection, which has a bandwidth of 4GBs, which bottlenecks the SSD However, PCIe Gen 4 increases the Solved: Does installing gen4 NVMe SSD on PCIe 3 slot affect the speed? or should i buy 3 gen3 NVMe ssd? Please give me some advice