ASRock B850M Pro-A

Name: ASRock B850M Pro-A
Brand: ASRock
SKU: 7390

Manufacturer: ASRock

The ASRock B850M Pro-A is a Micro-ATX motherboard designed for AMD AM5 processors, pairing the B850 chipset with a compact 244 x 244 mm footprint that suits space-conscious builds without sacrificing core functionality. It carries a three-year warranty and supports easy overclocking, making it a practical option for users who want tuning flexibility within a smaller chassis. The board ships without onboard Wi-Fi or Bluetooth, so connectivity relies on wired networking via its single RJ45 port.

On the memory side, the B850M Pro-A accommodates four DDR5 slots across two channels, supporting up to 256 GB at speeds reaching 8000 MHz. Storage options are well-covered through three M.2 sockets and four SATA 3 connectors, with RAID 0, 1, and 10 configurations available. Expansion is anchored by a single PCIe 5.0 x16 slot alongside a PCIe x4 slot. The rear I/O includes HDMI 2.1, one DisplayPort output, USB 3.2 Gen 2 ports in both Type-A and Type-C formats, and four USB 2.0 ports, while the board delivers 7.1-channel audio through three audio connectors.

Pros

Supports DDR5 memory across four slots with a maximum capacity of 256 GB, offering substantial headroom for memory-intensive workloads
Includes three M.2 sockets alongside four SATA 3 connectors, providing flexible storage configuration options
Features a PCIe 5.0 x16 slot, enabling compatibility with current-generation expansion cards
Dual BIOS adds a layer of firmware resilience, reducing the risk of a failed update rendering the board unusable
Overclocking is supported, with RAM speeds reachable up to 8000 MHz
Backed by a three-year warranty, which is a solid coverage period for a motherboard

Cons

No Wi-Fi or Bluetooth support, meaning wireless connectivity requires a separate adapter
Does not include an easy CMOS reset mechanism, which can complicate BIOS recovery in certain situations
No USB 4, Thunderbolt 3, or Thunderbolt 4 ports, limiting high-speed peripheral options on the rear I/O
ECC memory is not supported, ruling out use cases that require error-correcting RAM
Lacks an S/PDIF Out port, which may be a drawback for users needing digital audio output

Who is this for?

This board suits builders who want a compact AM5 system without sacrificing storage or memory expandability. With three M.2 sockets, four SATA 3 connectors, and support for up to 256 GB of DDR5 RAM, it handles demanding desktop workloads and content creation tasks well within a Micro-ATX footprint. The dual BIOS and overclocking support also make it a reasonable fit for enthusiasts who like to tune their system and want a safety net against firmware issues, while the PCIe 5.0 x16 slot ensures compatibility with current-generation discrete graphics cards.

Who is this NOT for?

Users who rely on wireless connectivity will find this board limiting, as neither Wi-Fi nor Bluetooth is built in, requiring an additional adapter. It is also a poor fit for workstation or server environments where ECC memory is a requirement for data integrity. Those who need high-speed peripheral connectivity through Thunderbolt or USB 4 will find the rear I/O insufficient for those use cases, and anyone requiring digital audio output via S/PDIF will need to look elsewhere.

General info:

CPU socket	AM5
chipset	B850
form factor	Micro-ATX
supports Wi-Fi	✕
Has Bluetooth	✕
HDMI version	HDMI 2.1
Easy to overclock	✓
has RGB lighting	✕
Easy to reset BIOS	✕
Has dual BIOS	✓
CPU sockets	1
Has integrated graphics	✕
warranty period	3 years
height	244 mm
width	244 mm
Has integrated CPU	✕

The ASRock B850M Pro-A uses an AM5 socket paired with a B850 chipset and comes in a Micro-ATX form factor measuring 244 x 244 mm, making it a compact but capable platform for AMD builds. It supports overclocking and features a dual BIOS for added firmware reliability, though it does not offer an easy CMOS reset button. The board outputs video via HDMI 2.1 but lacks integrated graphics and has no integrated CPU. Wi-Fi and Bluetooth are not included, and there is no RGB lighting on the board. A single CPU socket is present, and the product is backed by a 3-year warranty.

Memory:

maximum memory amount	256GB
RAM speed (max)	8000 MHz
overclocked RAM speed	8000 MHz
memory slots	4
DDR memory version	5
memory channels	2
Supports ECC memory	✕

The board supports DDR5 memory across four slots arranged in a dual-channel configuration, with a maximum supported capacity of 256 GB. RAM speeds reach up to 8000 MHz, which also represents the ceiling for overclocked operation. ECC memory is not supported.

Ports:

USB 3.2 Gen 2 ports (USB-A)	1
USB 3.2 Gen 1 ports (USB-A)	2
USB 3.2 Gen 2 ports (USB-C)	1
USB 3.2 Gen 1 ports (USB-C)	0
USB 2.0 ports	4
USB 3.2 Gen 2x2 ports	0
USB 4 40Gbps ports	0
USB 4 20Gbps ports	0
Thunderbolt 4 ports	0
Thunderbolt 3 ports	0
has an HDMI output	✓
DisplayPort outputs	1
RJ45 ports	1
Has USB Type-C	✓
eSATA ports	0
DVI outputs	0
has a VGA connector	✕
PS/2 ports	0

The rear I/O panel offers a varied USB lineup, including one USB 3.2 Gen 2 port in both Type-A and Type-C formats, two USB 3.2 Gen 1 Type-A ports, and four USB 2.0 ports. Higher-bandwidth options such as USB 3.2 Gen 2x2, USB 4, Thunderbolt 3, and Thunderbolt 4 are not present. Video output is handled by an HDMI port and one DisplayPort output, while VGA and DVI connections are absent. Wired networking is covered by a single RJ45 port, and there are no eSATA or PS/2 ports on the board.

Connectors:

USB 3.2 Gen 1 ports (through expansion)	4
USB 2.0 ports (through expansion)	4
SATA 3 connectors	4
fan headers	5
USB 3.0 ports (through expansion)	4
M.2 sockets	3
Has TPM connector	✓
U.2 sockets	0
Has mSATA connector	✕
SATA 2 connectors	0

Internal connectivity is well-provisioned, with three M.2 sockets and four SATA 3 connectors available for storage devices, while SATA 2, mSATA, and U.2 connections are not included. Expansion headers allow for four additional USB 3.2 Gen 1 ports, four USB 3.0 ports, and four USB 2.0 ports through compatible front-panel connectors. The board also provides five fan headers for cooling management and includes a TPM connector for hardware-based security modules.

Expansion slots:

PCIe 4.0 x16 slots	0
PCIe 5.0 x16 slots	1
PCIe 3.0 x16 slots	0
PCIe x1 slots	0
PCI slots	0
PCIe 2.0 x16 slots	0
PCIe x4 slots	1
PCIe x8 slots	0

The board offers a focused expansion slot layout, featuring one PCIe 5.0 x16 slot as the primary option for discrete graphics or other high-bandwidth cards, alongside one PCIe x4 slot for additional expansion needs. No PCIe 4.0, 3.0, or 2.0 x16 slots are present, and there are no PCIe x1, PCIe x8, or legacy PCI slots on the board.

Audio:

audio channels	7.1
Has S/PDIF Out port	✕
audio connectors	3

The board delivers 7.1-channel audio output through three analog audio connectors on the rear I/O. An S/PDIF Out port is not included for digital audio passthrough.

Storage:

Supports RAID 1	✓
Supports RAID 10 (1+0)	✓
Supports RAID 5	✕
Supports RAID 0	✓
Supports RAID 0+1	✕

The board supports RAID 0, 1, and 10 configurations for flexible storage setup and redundancy options. RAID 5 and RAID 0+1 are not supported.

Final Verdict

The ASRock B850M Pro-A is a well-specified Micro-ATX motherboard that delivers a strong feature set for its form factor, particularly for users building compact AM5 systems who still want meaningful storage and memory flexibility. Its three M.2 sockets, 256 GB DDR5 support, and PCIe 5.0 x16 slot ensure the platform remains capable and relevant for current-generation builds, while the dual BIOS and overclocking headroom add practical value for enthusiast users. The absence of wireless connectivity and ECC support narrows its appeal for certain workloads, but for mainstream desktop builds where wired connectivity is acceptable, the B850M Pro-A represents a thoughtfully equipped board within a compact chassis.