Open Box: Images shown are from the NEW version of this item and are for reference only. The actual Open Box product may differ in packaging and included accessories, but has been tested to ensure basic functionality.
ASUS Prime B550M-A/CSM AMD AM4 (3rd Gen Ryzen) microATX Commercial Motherboard (PCIe 4.0, ECC Memory, 1Gb LAN, HDMI 2.1/D-Sub, 4K@60HZ, TPM, ASUS Control Center Express)
Newegg only guarantees your receipt of the Open Box product with the purchase of this item. Any accessories MAY OR MAY NOT be included. Newegg will NOT send you any missing accessories, even if it is required to use all of the item’s functions.Open Box items usually do not come with manufacturer or vendor warranty or technical support. However, warranty support may be available if an item was never registered by a previous owner. Please contact the manufacturer to check.
3rd Gen AMD Ryzen Processors 1 x PCIe 4.0 x16 (x16 mode) 3rd Gen AMD Ryzen with Radeon Graphics Processors 1 x PCIe 3.0 x16 (x16 mode)
PCI Express x1
AMD B550 Chipset 2 x PCIe 3.0 x1 slots * Support PCIe bifurcation for RAID on CPU function.
4 x SATA 6Gb/s
3rd Gen AMD Ryzen Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110 (PCIE 4.0 x4 and SATA modes) storage devices support 3rd Gen AMD Ryzen with Radeon Graphics Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110 (PCIE 3.0 x4 and SATA modes) storage devices support AMD B550 Chipset: 1 x M.2_2 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support
Onboard Video Chipset
Supported only by CPU with integrated graphic: 1 x D-Sub 1 x DVI-D 1 x HDMI 2.1 (4K@60HZ)
7.1 Channels * A chassis with an HD audio module in the front panel is required to support 7.1-channel audio output.
Max LAN Speed
Rear Panel Ports
Back I/O Ports
2 x USB 3.2 Gen 2 ports (2 x Type-A) 4 x USB 3.2 Gen 1 ports (4 x Type-A) 1 x D-Sub port 1 x DVI-D port 1 x HDMI port 1 x Realtek RTL8111H 1Gb Ethernet port 3 x Audio jacks 1 x PS/2 Keyboard/Mouse combo port
Internal I/O Connectors
1 x USB 3.2 Gen 1 header supports additional 2 USB 3.2 Gen 1 ports 2 x USB 2.0 headers support additional 4 USB 2.0 ports
1 x CPU Fan connector(s) 1 x CPU OPT Fan connector(s) 2 x Chassis Fan connector(s) 2 x Aura RGB Strip Headers 1 x Addressable Gen 2 header(s) 1 x SPI TPM header 1 x S/PDIF out header(s) 1 x Front panel audio connector(s) (AAFP) 1 x Clear CMOS jumper(s) 1 x System panel connector 1 x COM port header 1 x Speaker connector
Dimensions (W x L)
9.6" x 9.6"
1 x 24-pin Main Power connector 1 x 8-pin +12V Power connector
Windows 11 Compatibility
Software Features: ASUS Exclusive Software Armoury Crate - Aura Creator - Aura Sync AI Suite 3 - Performance And Power Saving Utility TurboV EVO EPU Digi+ VRM Fan Xpert 2+ - EZ update ASUS CPU-Z AI Charger DAEMON Tools Norton Anti-virus software (Free Trial for 60 days) WinRAR UEFI BIOS ASUS EZ DIY - ASUS CrashFree BIOS 3 - ASUS EZ Flash 3 - ASUS UEFI BIOS EZ Mode
ASUS Special Features: ASUS 5X PROTECTION III - ASUS DIGI+ VRM - ASUS LANGuard - ASUS Overvoltage Protection - ASUS SafeSlot Core - ASUS Stainless-Steel Back I/O ASUS Q-Design - ASUS Q-DIMM - ASUS Q-Slot ASUS Thermal Solution - Aluminum heatsink design AURA Sync - Standard RGB headers - Addressable Gen 2 RGB header ASUS Lighting Control