ASROCK B550M Pro4 AM4 Socket DDR4 4733+ 1 x3.0 x16 x4.0 PCIe HDMI D-Sub DisplayPort 7.1 CH HD 6 SATA3 2 USB 3.2 mATX MBASROCK B550M Pro4 AM4 mATX MB ASROCK B550M Pro4 AM4 Socket DDR4 4733+ 1 x3. 0 x16 x4. 0 PCIe HDMI D Sub DisplayPort 7. 1 CH HD 6 SATA3 2 USB 3. 2 mATX MB AMD B550 SAM4 Micro ATX DDR4 4733 4666 4600 4533 4466 4400 4333 4266 4200 4133 4000 3866 3800 3733 3600 3466 3200 2933 2666 2400 2133 MHz Memory slots 4 1xPCI Express 3. 0 1x 1xPCI Express 3. 0 16x 1xPCI Express 4. 0 16x 1xM. 2 1x15pin D sub 1xHDMI 1xDisplayPort 2xUSB 2. 0 5xUSB 3. 2 1xUSB C 1xPS 2