ASROCK ATX motherboard B850 PRO-A AM5 DSP0000042378

Features of the ASRock B850 Pro-A
The ASRock B850 Pro-A is an ATX motherboard designed for systems based on AMD Ryzen processors with an AM5 socket. Equipped with the AMD B850 chipset, it combines support for DDR5 memory, PCIe 5.0 connectivity, high-speed M.2 storage and a robust power configuration, providing a platform ready for both everyday systems and high-performance builds.
Compatible with AMD Ryzen processors AM5
The B850 Pro-A uses the AMD AM5 socket and is compatible with AMD Ryzen 9000, 8000 and 7000 Series processors. The features and speeds available on certain PCIe and M.2 ports may vary depending on the installed processor family.

Socket : AMD AM5
Compatible processors: AMD Ryzen 9000, 8000 and 7000 Series
Chipset : AMD B850
The availability and speed of certain slots depend on the installed CPU

Robust power delivery and 8-layer PCB
Its 14+2+1-phase power delivery system with 80 A Dr.MOS for VCore, SoC and MISC is designed to provide stable power to the processor. It also features an 8-layer PCB and two high-density 8-pin CPU power connectors.

Power design: 14+2+1 phases
80 A Dr.MOS for VCore + SoC + MISC
8-layer PCB
1 24-pin ATX connector
2 high-density 8-pin 12 V power connectors

DDR5 memory up to 256 GB
The motherboard features four DDR5 DIMM slots in a Dual Channel configuration, with a maximum capacity of 256 GB. It supports ECC and non-ECC un-buffered memory and speeds of up to 8000+ MT/s via overclocking, as well as XMP and AMD EXPO profiles.

Dual Channel technology DDR5
4 slots DDR5 DIMM
Maximum capacity : 256 GB
Supports DDR5 ECC and non-ECC un-buffered memory
Supported speed: up to DDR5 8000+ (OC)
Compatible with XMP and AMD EXPO profiles

PCIe 5.0 for graphics cards
The primary slot offers PCIe 5.0 x16 connectivity with Ryzen 9000 and 7000 processors, allowing you to take advantage of high-speed expansion cards. The motherboard also includes a second PCIe slot and an M.2 Key E connector for WiFi and Bluetooth modules.

1 PCIe 5.0 x16 (PCIE1) connected to the CPU
PCIE1 operates at Gen5 x16 with Ryzen 9000 and 7000
PCIE1 operates at Gen4 x8 with Ryzen 8000 Phoeni x 1
PCIE1 operates at Gen4 x4 with Ryzen 8000 Phoeni x 2
1 PCIe 4.0 x16 (PCIE2) operating at up to x4
1 M.2 Key E socket for PCIe-type WiFi/Bluetooth modules 2230
15 µ gold contacts in the main PCIe slot
If M2_3 is occupied, PCIE2 is disabled
Compatible with NVMe SSDs as boot drives

Four M.2 slots and SATA connectivity
For storage, the ASRock B850 Pro-A offers four M.2 slots, including a PCIe Gen5 x4 interface capable of reaching a bandwidth of up to 128 Gb/s. It also has four 6 Gb/s SATA3 connectors for conventional storage drives.

1 Blazing M.2 M2_1, Key M, type 2280, PCIe Gen5 x4 up to 128 Gb/s
1 Hyper M.2 M2_2, Key M, type 2280, PCIe Gen4 x4 up to 64 Gb/s
1 Hyper M.2 M2_3, Key M, types 2230/2242/2260/2280, PCIe Gen4 x4 up to 64 Gb/s
1 Ultra M.2 M2_4, Key M, type 2280, PCIe Gen3 x4 up to 32 Gb/s
2 6 Gb/s SATA3 connectors via chipset
2 6 Gb/s SATA3 connectors via ASMedia controller ASM1061
Compatible with NVMe SSDs as boot drives

The M2_1 slot is the preferred location for installing an M.2 drive. It operates at Gen5 x4 with Ryzen 9000 and 7000 processors, and at Gen4 x4 with Ryzen 8000 Phoenix 1 and Phoenix 2. M2_2 operates at Gen4 x4 with Ryzen 9000, 7000 and 8000 Phoenix 1, and at Gen4 x2 with Ryzen 8000 Phoenix 2.

If M2_3 is occupied, PCIE2 is disabled
If SATA3_1 or SATA3_2 are occupied, M2_4 reduces its operation to Gen 3 x2

RAID support for SATA and NVMe
The motherboard allows you to create RAID configurations with both SATA drives and M.2 NVMe storage, providing flexibility for setups focused on performance or data redundancy.

RAID 0 and RAID 1 for SATA devices
RAID 0, RAID 1 and RAID 10 for M.2 NVMe devices

Integrated graphics and output up to 4K
When using a processor with compatible AMD RDNA integrated graphics, the motherboard allows monitors to be connected via HDMI 2.1 or USB-C with DisplayPort Alt Mode. The HDMI output supports resolutions up to 4K at 120 Hz.

Compatible with integrated AMD RDNA graphics, depending on CPU
1 HDMI 2.1 TMDS/FRL 8G
HDR support and HDCP 2.3
Maximum HDMI resolution: 4K at 120 Hz
1 USB 3.2 Gen1 Type-C with DisplayPort 1.4 HBR3
DisplayPort Alt Mode compatible with DP 1.4a
Maximum resolution via USB-C DisplayPort: 4K at 60 Hz

2.5 Gigabit network with Dragon controller
Network connectivity is managed by the Dragon RTL8125BG 2.5 GbE controller, with speeds of up to 2500 Mb/s and dedicated software for managing bandwidth and setting priorities according to usage type.

2.5 Gigabit Ethernet LAN
Speeds: 10/100/1000/2500 Mb/s
Dragon controller RTL8125BG
Compatible with Dragon 2.5G LAN Software
Intelligent, automatic bandwidth control
Visual user interface
Visual network usage statistics
Configurations optimized for gaming, browsing and streaming
Customisable priority control

7.1-channel HD audio
The integrated sound system uses the Realtek ALC897 codec, providing HD audio with up to 7.1 channels for multimedia and entertainment setups.

7.1-channel HD audio
Realtek codec ALC897
Rear Line In, Front Speaker and Microphone connectors
Internal front-panel audio connector

Extensive USB connectivity
The B850 Pro-A offers a wide range of USB connections, including front-panel USB 3.2 Gen2x2 Type-C with speeds of up to 20 Gb/s, as well as rear Type-C and Type-A connections. All USB ports feature ESD protection.

1 rear USB 3.2 Gen2 Type-C connected to the CPU
1 rear USB 3.2 Gen1 Type-C connected to the CPU
2 rear USB 3.2 Gen1 Type-A connected to the CPU
1 front USB 3.2 Gen2x2 Type-C connected to the chipset
4 USB 3.2 Gen1 Type-A via chipset: 2 rear and 2 front
9 USB 2.0 via chipset: 6 rear and 3 front
All USB ports feature ESD protection

Internal connectors for cooling and lighting
The motherboard provides numerous connectors for fans, AIO pumps and lighting, making it easy to configure systems with cooling and customizable RGB effects. The fan connectors support intelligent speed control.

1 SPI TPM connector
1 Power LED and Speaker connector
1 RGB LED connector
3 Addressable LED connectors
2 4-pin CPU Fan connectors with Smart Fan Speed Control
4 4-pin Chassis Fan connectors with Smart Fan Speed Control
1 4-pin AIO Pump Fan connector with Smart Fan Speed Control
1 internal USB 3.2 Gen1 connector for 2 ports
2 internal USB 2.0 connectors supporting 3 ports
1 front USB Type-C 3.2 Gen2x2 connector at 20 Gb/s
The RGB connector supports LED strips up to 12 V / 3 A / 36 W
The Addressable LED connectors support a total of up to 5 V / 3 A / 15 W

The CPU_FAN1 connector supports up to 1 A or 12 W, while CPU_FAN2, CHA_FAN1 to CHA_FAN4 and AIO_PUMP support up to 3 A or 36 W. The latter can automatically detect whether a 3- or 4-pin fan is being used.
Rear panel with BIOS Flashback
The rear I/O panel integrates the board’s main ports and a BIOS Flashback button, designed to make it easy to update or recover the firmware without needing to access the operating system.

2 antenna mounting points
1 HDMI port
1 USB 3.2 Gen2 Type-C, 10 Gb/s
1 USB 3.2 Gen1 Type-C with DisplayPort Alt Mode DP 1.4a
4 USB 3.2 Gen1 Type-A
6 USB 2.0
1 port RJ-45 LAN
1 BIOS Flashback button
HD Audio connectors: Line In, Front Speaker and Microphone

UEFI and ASRock tools
The motherboard includes a 256 Mb AMI UEFI BIOS with a graphical interface and various ASRock tools designed to simplify system configuration, driver updates, monitoring and customisation.

256 Mb AMI UEFI BIOS with GUI support
ASRock EZ Mode
ASRock Full HD UEFI
ASRock Auto Driver Installer
ASRock Instant Flash
ASRock Motherboard Utility (A-Tuning)
ASRock Dragon 2.5G LAN Software
ASRock Polychrome Sync
Software tools can be downloaded via Live Update & APP Shop
ASRock Post Status Checker for easier system diagnostics

ATX form factor and Windows compatibility
With an ATX form factor of 30.5 x 24.4 cm, this motherboard is designed for cases compatible with this standard. It offers official support for 64-bit Microsoft Windows operating systems.

Format: ATX
Dimensions: 12.0 x 9.6 inches
Dimensions: 30,5 x 24,4 cm
8-layer PCB
Compatible with 64-bit Microsoft Windows 10
Compatible with 64-bit Microsoft Windows 11

Included accessories and certifications
The ASRock B850 Pro-A is supplied with the essential accessories for installation and connection, including the rear I/O shield, SATA cables and an M.2 drive screw.

1 I/O Shield
2 SATA data cables
1 socket screw M.2
FCC and CE certifications
ErP/EuP compatible when used with an ErP/EuP-compatible power supply
Volume (m ³): 0.0091