Using LSI 2308 in PCIE x1 mode, what will I lose?

PCI Slot x 3 30423052 B-Key x 1 Mini PCIe Slot x 1 Micro SIM Card Slot x 1

The number after the x tells you how many lanes that PCIe slot has A PCIe x1 slot has one lane and

pcie 20 x16 slot PCIe Gen 3 was unable to accommodate the full bandwidth of high-speed PCIe NVMe SSDs This was effectively creating a bottleneck in SSD performance PCIe Gen 4

pcie slot function List of Motherboards with 2 PCI-Express x1 Slots: ASRock B760M-H, ASRock H610MAC, ASRock B760M-HDV, ASUS ROG Strix B760-A Gaming WiFi,