Unbearably Slow PCIe Gen 4 NVME Speeds ard

You can use a PCI-e card in a PCI-e slot but it will just work at PCI-e speed Not sure if you will really notice the speed

The Samsung SSD 970 EVO Plus is a client PC NVMe SSD with 3-bit MLC V-NAND Kingston Fury Renegade NVMe Gen 4 SSD 1TB The Kingston Fury Renegade

candy tower slot As far as I know both PCI-e slots and devices are backwards compatible A PCI-e nvme will work on a pci-e slot as far as I know

can you buy a slot machine Yes, PCIe is both forwards and backwards compatible For example, this gen 4 NVMe SSD will work in a gen 3 PCIe slot, and a gen 3 NVMe SSD would also work