Quick overview from the supplier:
MB AM4 ASRock B550 PHANTOM GAMING 4/AC ATX
// CPU
- AMD AM4 Socket
- Supports 3rd Gen AMD AM4 Ryzen™ / future AMD Ryzen™ Processors*
Chipset
- AMD B550
Memory
- Dual Channel DDR4 Memory Technology
- 4 x DDR4 DIMM Slots
- Supports DDR4 4733+ (OC)
- Max. capacity of system memory: 128GB**
Graphics
- Integrated AMD Radeon Vega Series Graphics in Ryzen Series APU*
- Shared memory default 2GB. Max Shared memory supports up to 16GB.**
- Supports HDMI 2.1 with max. resolution up to 4K x 2K (4096x2160) @ 60Hz
Audio
- 7.1 CH HD Audio with Content Protection (Realtek ALC1200 Audio Codec)
LAN
- PCIE x1 Gigabit LAN 10/100/1000 Mb/s
- Realtek RTL8111H
Wireless LAN
- Intel® 802.11ac WiFi Module
- Supports IEEE 802.11a/b/g/n/ac
- Supports Dual-Band (2.4/5 GHz)
- Supports Bluetooth 4.2 + High speed class II
Slots
- 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3: Gen3 x4 mode)*
- 2 x PCI Express 3.0 x1 Slots
- Supports AMD Quad CrossFireX™ and CrossFireX™
- 1 x M.2 Socket (Key E) with the bundled WiFi-802.11ac module
Storage
- 4 x SATA3 6.0 Gb/s Connectors, support RAID (RAID 0, RAID 1 and RAID 10), NCQ, AHCI and Hot Plug
- 1 x Hyper M.2 Socket (M2_1), supports M Key type 2260/2280/22110 M.2 PCI Express module up to Gen4x4 (64 Gb/s) (with Matisse) or Gen3x4 (32 Gb/s)*
USB
- 8 x USB 3.2 Gen1 Ports
- 4 x USB 2.0 Ports
https://www.asrock.com/mb/AMD/B550%20Phantom%20Gaming%204ac/index.asp#Overview
