MBP mid-2015 SSD is PCIe or ?

What does the X4 mean in an PCIe Gen X4 NVME drive? can i use pcie 3 0 in 2 0 slot AMD A620 ATX motherboard with DDR5, PCIe support, dual slots, Q-Latch, 12+2 DrMOS, Wi-Fi 6, Realtek Ethernet, DisplayPort, HDMI™, candy blitz slot Yes, a PCIe is backwards compatible with PCIe slots, and hence it will fit Although your performance will be limited by your PCIe slot

candy pop slot Regarding the white PCIe slot, is it a PCIe ? Have a nice day Was PCIe X4 converter which will be in PCIe ? Which one do you