therboards that support PCIE split, please refer to the following link
https://www.asus.com/tw/support/FAQ/1037507
For ASRock motherboards that support PCIE split, please refer to the following link
https://www.asrock.com/mb/spec/product.cn.asp?Model=ULTRA%20QUAD%20M.2%20CARD#SupportList
Server motherboards, X299 and X399 motherboards have split function
2.CPU support is required, and the CPU must have enough channels. Generally, low‑end CPUs do not have enough PCIE channels, so they may not be able to support it either. When purchasing a CPU, you can refer to the motherboard introduction to make the correct choice.
Specification:
Item Type: Adapter Card
Model: PH44
Support Hard Disk: M.2 NVME Protocol SSD / M.2 PCIE Equipment
Transmission Speed: 4 x 32Gbps
Package List:
1 x Adapter Card
4 x Nuts
5 x Screws
1 x Screwdriver