PCIe Gen 4 vs Gen 3 Slots, Speeds

PCIe slot will run at the lowest denomination speed The most common PCIe slot currently in use are PCIe x16 slots, PCIe x4

List of Motherboards with 3 PCI-Express x16 Slots: GIGABYTE B650 Gaming X AX V2, MSI X670E Gaming Plus WiFi, ASUS ROG Strix Z790-E Gaming WiFi II,

pcie 30 in 40 slot So, to answer your original question, if you're happy to abandon any other PCI devices you currently have, you can choose a motherboard with more PCIe x1 slots;

pcie 50 x16 slot List of Motherboards with 4 PCI-Express x16 Slots: ASUS Pro WS TRX50-SAGE WIFI, GIGABYTE A620M C, GIGABYTE B650M C V2, ASUS Prime B760M-A AX, GIGABYTE B760M