3 Things to Know About the Gigabyte B450M DS3H’s PCIe Slots
The board has one PCIe 3.0 x16 slot for your graphics card. That is the only full-size slot, and it runs at Gen 3 speeds.
You get two PCIe 2.0 x1 slots for smaller expansion cards. These are fine for Wi-Fi adapters or sound cards but not for high-bandwidth devices.
There is no PCIe Gen 4 support. This is a budget board, so it sticks with Gen 3. That is fine for most users, but do not expect future-proofing for faster SSDs or GPUs.