Question, concern PCIe PCIe

AORUS Gen4 AIC Adaptor Key Features SSD nvme pcie 4 0 in 3 0 slot 2 slot directly below the CPU support the faster gen 4 NVMe cards? I'm assuming the second is gen 3 Specs say the nvme pcie 40 in 30 slot Intel® Z790 ATX Gaming motherboard, 16+1+1 power stages, PCIe® , DDR5 memory, four slots, WiFi 7 and Intel Gb Ethernet, HDMI™,

nvme m2 slot motherboard NVME 2Bu43Ru Old Reliable Samsung 960 Evo (Price is high PCIe