Is it okay to put Gen 3 SSD in my motherboards Gen 4 pcie slots?

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and USB ; all these standards are backward compatible A Samsung 980 PRO PCIe NVMe SSD with 1 TB of storage capacity

PCIe x16 to 4 Ports NVMe-compatible Expansion Card PCI-E 16x 4 sold Linkreal GPU Expansion Solution PCIe Retimer and PCIe Slot adapter with SFF- You're referring to NVME based M2 SSDs, correct? But yes if the SSD is PCIE spec then of course the speed will be less when used on PCIE

coyote moon slot game online free 2 SATA type drives only You would need either a card that has 2 NVMe slots, or two seperate cards that each have an NVMe slot  when looking at NVMe SSDs With the previous generation, the maximum bandwidth available on an slot with its four PCIe lanes was 4GB