We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Micro ATX motherboard in matte black with silver heatsinks, AM5 socket, four DDR5 slots, PCIe 5.0 x16 slot, HDMI and DisplayPort

ASRock

ASRock B850M Pro RS AMD motherboard

SKU CH-9BKZ-BEQ6A MPN B850M Pro RS

Micro-ATX AM5 board with one PCIe 5.0 x16 slot, one Gen5 M.2 and two Gen4 M.2 slots, plus 4 DDR5 DIMMs up to 256 GB

  • CPU Socket TypeAM5
  • CPU TypeRyzen 7000 Series / Ryzen 8000 Series / Ryzen 9000 Series
  • ChipsetAMD B850
  • Number of Memory Slots4x288pin (DDR5)
  • Memory StandardUp to 8000+(OC)
  • Maximum Memory Supported256GB

Option B850M Pro RS

Struck-through versions exist but are not stocked here.

  • Supports Ryzen 9000, 8000 and 7000 series processors via AM5 socket
  • 8+2+1 phase Dr.MOS power design delivers stable CPU current
  • Four DDR5 slots accept up to 256 GB at 8000+ OC
  • One PCIe 5.0 x16 slot plus one PCIe 4.0 x4 slot
  • One Blazing M.2 Gen5x4 128 Gb/s plus two Hyper M.2 Gen4x4 64 Gb/s

Socket AM5 micro-ATX board

The ASRock B850M Pro RS is a micro-ATX motherboard built on the AMD B850 chipset for Socket AM5 processors. It accepts Ryzen 7000, 8000 and 9000 series CPUs and provides four DDR5 DIMM slots with dual-channel support up to 256 GB. An 8+2+1 phase Dr.MOS power design and a 6-layer PCB deliver stable current for daily workloads and moderate overclocking.

Builders wanting Gen5 graphics and fast storage

This board suits builders who need a single PCIe 5.0 x16 slot for a modern graphics card and a CPU-linked Blazing M.2 socket running at Gen5 x4 speeds. Two additional chipset M.2 sockets operate at Gen4 x4. Users requiring multiple PCIe 5.0 x16 slots or more than three M.2 connectors should look at larger ATX models.

One PCIe 5.0 x16 slot runs at x16 with Ryzen 9000

The primary PCIe 5.0 x16 slot operates at Gen5 x16 with Ryzen 9000 and 7000 series processors, dropping to Gen4 x8 with Ryzen 8000 Phoenix 1 and Gen4 x4 with Phoenix 2. This lane allocation decides whether a high-end GPU receives full bandwidth.

Highlights

  • Supports Ryzen 9000, 8000 and 7000 series processors via AM5 socket
  • 8+2+1 phase Dr.MOS power design delivers stable CPU current
  • Four DDR5 slots accept up to 256 GB at 8000+ OC
  • One PCIe 5.0 x16 slot plus one PCIe 4.0 x4 slot
  • One Blazing M.2 Gen5x4 128 Gb/s plus two Hyper M.2 Gen4x4 64 Gb/s

Specifications

BrandASRock
ModelB850M Pro RS
CPU Socket TypeAM5
CPU TypeRyzen 7000 Series / Ryzen 8000 Series / Ryzen 9000 Series
ChipsetAMD B850
Number of Memory Slots4x288pin (DDR5)
Memory StandardUp to 8000+(OC)
Maximum Memory Supported256GB
Channel SupportedDual Channel
Memory Performance ProfileAMD EXPO / Intel XMP 3.0
ECC SupportedYes
Buffer SupportedUn-buffered
PCI Express 5.0 x161 x PCIe 5.0 x16 Slot (PCIE1), supports x16 mode*
* PCIE1 will run at Gen5x16 with 9000 and 7000 series processors, Gen4x8 with 8000 (Phoenix 1) series processors and Gen4x4 with 8000 (Phoenix 2) series processors.
* If M2_3 is occupied, PCIE2 will be disabled.
* Supports NVMe SSD as boot disks
- 15µ Gold Contact in VGA PCIe Slot (PCIE1)
PCI Express 4.0 x161 x PCIe 4.0 x4 Slot (PCIE2), supports x4 mode*
Serial ATA (SATA)4 x SATA 6Gb/s
M.2CPU:
- 1 x Blazing M.2 Socket (M2_1, Key M), supports type 2280 PCIe Gen5x4 (128 Gb/s) mode*
Chipset:
- 1 x Hyper M.2 Socket (M2_2, Key M), supports type 2280 PCIe Gen4x4 (64 Gb/s) mode*
- 1 x Hyper M.2 Socket (M2_3, Key M), supports type 2280 PCIe Gen4x4 (64 Gb/s) mode*
* Supports NVMe SSD as boot disks
* M2_1 is the first priority for M.2 installation.
* M2_1 will run at Gen5x4 with 9000 and 7000 series processors and Gen4x4 with 8000 (Phoenix 1 and Phoenix 2) series processors.
* M2_3 will run at Gen4x4 with 9000 and 7000 series processors, Gen4x4 with 8000 (Phoenix 1) series proc
SATA RAIDSupports RAID 0, RAID 1 and RAID 10 for SATA storage devices
Supports RAID 0, RAID 1 and RAID 10 for M.2 NVMe storage devices*
* Requires additional M.2 NVMe expansion cards to support RAID 10
Audio ChipsetRealtek ALC897
Audio Channels7.1 Channels
LAN ChipsetDragon RTL8125BG
Max LAN Speed2.5Gbps
Back I/O Ports2 x Antenna Mounting Points
1 x HDMI Port
1 x DisplayPort 1.4
1 x USB 3.2 Gen2 Type-A Port (10 Gb/s)
1 x USB 3.2 Gen2 Type-C Port
2 x USB 3.2 Gen1 Ports
4 x USB 2.0 Ports
1 x RJ-45 LAN Port
1 x BIOS Flashback Button
HD Audio Jacks: Line in / Front Speaker / Microphone
Onboard USB2 x USB 2.0 Headers (Support 4 USB 2.0 ports)
2 x USB 3.2 Gen1 Headers (Support 4 USB 3.2 Gen1 ports)
1 x Front Panel Type C USB 3.2 Gen1 Header
Other Connectors1 x SPI TPM Header
1 x Power LED and Speaker Header
1 x RGB LED Header*
3 x Addressable LED Headers**
2 x CPU Fan Connectors (4-pin) (Smart Fan Speed Control)***
3 x Chassis Fan Connectors (4-pin) (Smart Fan Speed Control)***
1 x Front Panel Audio Connector
* Supports in total up to 12V/3A, 36W LED Strip
** Support in total up to 5V/3A, 15W LED Strip
*** CPU_FAN1 supports the fan power up to 1A (12W).
*** CPU_FAN2 and CHA_FAN1~3 support the fan power up to 3A (36W).
*** CPU_FAN2 and CHA_FAN1~3 can auto detect if 3-pin or 4-pin fan is in use.
Form FactorMicro ATX
Dimensions (W x L)9.6" x 9.6"
Power Pin1 x 24 pin ATX Power Connector
1 x 8 pin 12V Power Connector (Hi-Density Power Connector)
1 x 4 pin 12V Power Connector (Hi-Density Power Connector)
BIOS Feature256Mb AMI UEFI Legal BIOS with GUI support
SoftwareSoftware
- ASRock Motherboard Utility (A-Tuning)
- ASRock Dragon 2.5G LAN Software
- ASRock Polychrome SYNC
* These utilities can be downloaded from ASRock Live Update & APP Shop.
UEFI
- ASRock EZ Mode
- ASRock Full HD UEFI
- ASRock Auto Driver Installer
- ASRock Instant Flash
Windows 11Windows OS 10 64-bit / 11 64-bit
FeaturesSuperb Productivity
- PCIe Gen5 (Graphics, M.2)
- Dual Channel DDR5
Rock-Solid Durability
- 8+2+1 Power Phase, Dr.MOS for VCore+SOC+MISC
- Pre-Installed I/O Shield
Ultrafast Connectivity
- 2.5G LAN
EZ Update
- BIOS Flashback Button
- ASRock Auto Driver Installer
EZ Troubleshooter
- ASRock Post Status Checker
Package Contents2 x SATA Data Cables
1 x Screw for M.2 Socket
Shipping weight1.36 kg
Package size292 × 254 × 64 mm

Other versions of this model

5 more in the same range

Same family, different memory, cooler or clock — compare before you commit.

Questions about this item

Will this board fit in a standard micro-ATX case and still leave room for a dual-slot graphics card?

Yes, the micro-ATX form factor fits any case that accepts that size, and the single PCIe 5.0 x16 slot is positioned so a dual-slot card clears the board edge and the front-panel headers.

Which Ryzen processors run the top PCIe slot at full Gen 5 x16 speed?

Ryzen 7000 and 9000 series CPUs drive the primary slot at Gen 5 x16; Ryzen 8000 series processors limit it to Gen 4 x8 or Gen 4 x4 depending on the specific silicon.

Can I populate all four DIMM slots with 64 GB modules to reach the 256 GB maximum?

Yes, the four 288-pin DDR5 slots support up to 256 GB total when using 64 GB unbuffered DIMMs, running in dual-channel mode with AMD EXPO or Intel XMP 3.0 profiles.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.