B550M/ac - Motherboard ASROCK - Free user manual and instructions

Product Type	Motherboard
Brand	ASRock
Model	B550M/ac
Form Factor	Micro ATX
Chipset	AMD B550
Processor Socket	AM4
Compatible Processors	AMD Ryzen 3000 and 4000 series (Matisse, Renoir) – except Ryzen 5 3400G and 3200G
Supported Memory	DDR4, 4 DIMM slots, max 128 GB, up to 4533+ MHz OC
Expansion Slots	2 x PCIe x16 (Gen4/Gen3 depending on CPU), 1 x PCIe 3.0 x1
SATA Storage	4 x SATA3 6 Gb/s (RAID 0, 1, 10)
M.2 Storage	1 x Hyper M.2 (2280, PCIe Gen4 x4 or Gen3 x4)
Wired Networking	Realtek RTL8111H Gigabit LAN
Wireless Networking	Intel Wi-Fi 802.11ac + Bluetooth 4.2
Audio	Realtek ALC1200, 7.1 CH HD, Nahimic
Video Connectors	1 x HDMI 2.1 (4K@60Hz, HDR, HDCP 2.3)
Rear USB Connectors	4 x USB 3.2 Gen1, 2 x USB 2.0
Internal USB Connectors	2 x USB 3.2 Gen1 headers (4 ports), 2 x USB 2.0 headers (4 ports)
Power Supply	ATX 24-pin + 8-pin 12V, Digi Power 8 phases
Fan Headers	1 x CPU fan 4-pin, 3 x chassis/pump 4-pin
BIOS	AMI UEFI with graphical interface
Operating System	Windows 10 64-bit
Certifications	FCC, CE, ErP/EuP

Frequently Asked Questions - B550M/ac ASROCK

Which processors are compatible with the ASRock B550M/ac motherboard?

The motherboard supports AMD Ryzen 3000 and 4000 series (Matisse and Renoir) on socket AM4. Excluded are Ryzen 5 3400G and 3200G.

How to update the motherboard BIOS?

Download the latest BIOS version from the ASRock website (http://www.asrock.com). Place the file on a USB flash drive formatted in FAT32, then use the Instant Flash tool in the UEFI BIOS.

What RAM is recommended for this model?

The motherboard supports DDR4 in dual-channel configuration, up to 128 GB. Consult the memory compatibility list (QVL) on the ASRock website for validated modules.

How to configure RAID with the SATA ports?

Connect the hard drives to the SATA3 ports. In the BIOS, enable RAID mode. During POST, press Ctrl+R to enter the AMD RAID utility and create RAID 0, 1, or 10 volumes.

Where to connect the supplied Wi-Fi antennas?

Screw the two Wi-Fi antennas into the connectors on the back of the motherboard, near the USB and HDMI ports. Ensure they are tightened for optimal connection.

Can I overclock the processor with this motherboard?

Yes, the motherboard allows overclocking via BIOS. However, overclocking carries risks of damage. ASRock assumes no liability. Use gradual adjustments and check stability.

How to connect RGB LED strips?

The motherboard has two RGB LED headers (12V/3A) and two addressable headers (5V/3A). Connect your strips respecting polarity and use the ASRock Polychrome Sync software to control them.

Can I use an M.2 NVMe SSD as a boot drive?

Yes, the motherboard supports NVMe SSDs as boot drives via the Hyper M.2 socket. Ensure the SSD is in 2280 form factor and PCIe compatible.

What to do if the motherboard does not start?

Check the power connections (24-pin and 8-pin), front panel cables, and that the processor is properly installed. Use the Clear CMOS jumper (CLRCMOS1) to reset the BIOS.

How to clear the BIOS settings (Clear CMOS)?

Turn off the computer and disconnect the power cable. Place a jumper cap on the CLRCMOS1 pins for 3 seconds, then remove it. Reconnect the power and restart.

USER MANUAL B550M/ac ASROCK

Copyright©2020 ASRock INC. All rights reserved.

Copyright Notice:

No part of this documentation may be reproduced, transcribed, transmitted, or translated in any language, in any form or by any means, except duplication of documentation by the purchaser for backup purpose, without written consent of ASRock Inc.

Products and corporate names appearing in this documentation may or may not be registered trademarks or copyrights of their respective companies, and are used only for identification or explanation and to the owners' benefit, without intent to infringe.

Disclaimer:

Specifications and information contained in this documentation are furnished for informational use only and subject to change without notice, and should not be constructed as a commitment by ASRock. ASRock assumes no responsibility for any errors or omissions that may appear in this documentation.

With respect to the contents of this documentation, ASRock does not provide warranty of any kind, either expressed or implied, including but not limited to the implied warranties or conditions of merchantability or fitness for a particular purpose.

In no event shall ASRock, its directors, officers, employees, or agents be liable for any indirect, special, incidental, or consequential damages (including damages for loss of profits, loss of business, loss of data, interruption of business and the like), even if ASRock has been advised of the possibility of such damages arising from any defect or error in the documentation or product.

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may cause undesired operation.

CALIFORNIA, USA ONLY

The Lithium battery adopted on this motherboard contains Perchlorate, a toxic substance controlled in Perchlorate Best Management Practices (BMP) regulations passed by the California Legislature. When you discard the Lithium battery in California, USA, please follow the related regulations in advance.

"Perchlorate Material-special handling may apply, see www.dtsc.ca.gov/hazardouswaste/perchlorate"

ASRock Website: http://www.asrock.com

AUSTRALIA ONLY

Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage caused by our goods. You are also entitled to have the goods repaired or replaced if the goods fail to be of acceptable quality and the failure does not amount to a major failure. If you require assistance please call ASRock Tel : [phone] ext.123 (Standard International call charges apply)

The terms HDMI ^® and HDMI High-Definition Multimedia Interface, and the HDMI logo are trademarks or registered trademarks of HDMI Licensing LLC in the United States and other countries.

CE Warning

This device complies with directive 2014/53/EU issued by the Commission of the European Community.

This equipment complies with EU radiation exposure limits set forth for an uncontrolled environment.

This equipment should be installed and operated with minimum distance 20cm between the radiator & your body.

Operations in the 5.15-5.35GHz band are restricted to indoor usage only.

	AT	BE	BG	CH	CY	CZ	DE
	DK	EE	EL	ES	FI	FR	HR
	HU	IE	IS	IT	LI	LT	LU
	LV	MT	NL	NO	PL	PT	RO
	SE	SI	SK	TR	UK

Radio transmit power per transceiver type

Function Frequency Maximum Output Power (EIRP)

	2400-2483.5 MHz 18.5 + / -1.5 dbm
	5150-5250 MHz 21.5 + / -1.5 dbm
WiFi	5250-5350 MHz	18.5 + / -1.5 dbm (no TPC)
		21.5 + / -1.5 dbm (TPC)
	5470-5725 MHz	25.5 + / -1.5 dbm (no TPC)
		28.5 + / -1.5 dbm (TPC)

Bluetooth 2400-2483.5 MHz 8.5 + / -1.5 dbm

Motherboard Layout

ATX 12V1 CPU_FAN ASRock B550M/ac DDR4_A1 (64 bit, 288-pin module) DDR4_A2 (64 bit, 288-pin module) DDR4_B1 (64 bit, 288-pin module) DDR4_B2 (64 bit, 288-pin module) RGB_LED1 ACCR_LED1 ATXPWR1 SPI_1PM_J1 Hyper M.2 USB3.2 PCIE1 Super I/O M2_1 PCIE2 WiFi-802.11ac Module CMOS Battery PCIE3 DC_AUDIO1 RCD_LED2 ADDR_LED2 USB 2.0 T:USB1 B:USB2 P5Z Mbps/Myosos USB 3.2 Gen1 T:USB1 B:USB2 USB 3.2 Gen1 T:USB1 B:USB4 RJ-5FLNM Micro Micro Micro LANE SATAA_4 SATA3_3 AMD Promontory B550 25 24 23 22 21 20 19 18 17 16 15 14 13 12 5 6 7 8 9 10 11

No. Description

1 8 pin 12V Power Connector (ATX12V1)

2 CPU Fan Connector (CPU_FAN1)

3 2 x 288-pin DDR4 DIMM Slots (DDR4_A1, DDR4_B1)

4 2 x 288-pin DDR4 DIMM Slots (DDR4_A2, DDR4_B2)

5 RGB LED Header (RGB_LED1)

6 Addressable LED Header (ADDR_LED1)

7 ATX Power Connector (ATXPWR1)

8 USB 3.2 Gen1 Header (F_USB3_1_2)

9 SATA3 Connector (SATA3_2)

10 SATA3 Connector (SATA3_1)

11 SATA3 Connector (SATA3_4)(Upper), SATA3 Connector (SATA3_3)(Lower)

12 System Panel Header (PANEL1)

13 Power LED and Speaker Header (SPK_PLED1)

14 USB 3.2 Gen1 Header (F_USB3_3_4)

15 Chassis/Water Pump Fan Connector (CHA_FAN4/WP)

16 Post Status Checker (PSC)

17 SPI TPM Header (SPI_TPM_J1)

18 USB 2.0 Header (USB_3_4)

19 USB 2.0 Header (USB_5_6)

20 Chassis/Water Pump Fan Connector (CHA_FAN2/WP)

21 Clear CMOS Jumper (CLRCMOS1)

22 COM Port Header (COM1)

23 Addressable LED Header (ADDR_LED2)

24 RGB LED Header (RGB_LED2)

25 Front Panel Audio Header (HD_AUDIO1)

26 Chassis/Water Pump Fan Connector (CHA_FAN1/WP)

I/O Panel

Diagram showing a sequence of electronic devices with numbered labels from 1 to 10, likely representing a device model or labeling system.

No. Description No. Description

1 USB 2.0 Ports (USB_12)* 6 USB 3.2 Gen1 Ports (USB3_34)

2 LAN RJ-45 Port** 7 USB 3.2 Gen1 Ports (USB3_12)

3 Line In (Light Blue)*** 8 PS/2 Mouse/Keyboard Port

4 Front Speaker (Lime)*** 9 HDMI Port

5 Microphone (Pink)*** 10 Antenna Ports

* Please note that the USB_2 consumes auxiliary power (+5VSB) while the other USB ports consume DUAL Power (+5VDUAL). The USB_2 is optimal for connecting the USB Type speaker and headset.

** There are two LEDs on each LAN port. Please refer to the table below for the LAN port LED indications.

Activity / Link LED Speed LED

Status Description Status Description

Off	No Link	Off	10Mbps connection
Blinking	Data Activity	Orange	100Mbps connection
On	Link	Green	1Gbps connection

*** Function of the Audio Ports in 7.1-channel Configuration:

Port Function
Light Blue (Rear panel) Rear Speaker Out
Lime (Rear panel) Front Speaker Out
Pink (Rear panel) Central /Subwoofer Speaker Out
Lime (Front panel) Side Speaker Out

WiFi-802.11ac Module and ASRock WiFi 2.4/5 GHz Antennas

WiFi-802.11ac + BT Module

This motherboard comes with an exclusive WiFi 802.11 a/b/g/n/ac + BT v4.2 module that offers support for WiFi 802.11 a/b/g/n/ac connectivity standards and Bluetooth v4.2. WiFi + BT module is an easy-to-use wireless local area network (WLAN) adapter to support WiFi + BT. Bluetooth v4.2 standard features Smart Ready technology that adds a whole new class of functionality into the mobile devices. BT 4.2 also includes Low Energy Technology and ensures extraordinary low power consumption for PCs.

* The transmission speed may vary according to the environment.

WiFi Antennas Installation Guide

Two identical cylindrical objects with segmented ends, no text or symbols visible

Technical line drawing of a mechanical assembly with two cylindrical components mounted on a base (no text or symbols)

Mechanical assembly diagram showing a lever mechanism with rotating components (no text or labels)

Step 1

Prepare the WiFi 2.4/5 GHz Antennas that come with the package.

Step 2

Connect the two WiFi 2.4/5 GHz Antennas to the antenna connectors. Turn the antenna clockwise until it is securely connected.

Step 3

Set the WiFi 2.4/5 GHz Antenna as shown in the illustration.

*You may need to adjust the direction of the antenna for a stronger signal.

Chapter 1 Introduction

Thank you for purchasing ASRock B550M/ac motherboard, a reliable motherboard produced under ASRock's consistently stringent quality control. It delivers excellent performance with robust design conforming to ASRock's commitment to quality and endurance.

Because the motherboard specifications and the BIOS software might be updated, the content of this documentation will be subject to change without notice. In case any modifications of this documentation occur, the updated version will be available on ASRock's website without further notice. If you require technical support related to this motherboard, please visit our website for specific information about the model you are using. You may find the latest VGA cards and CPU support list on ASRock's website as well. ASRock website http://www.asrock.com.

1.1 Package Contents

• ASRock B550M/ac Motherboard (Micro ATX Form Factor)
• ASRock B550M/ac Quick Installation Guide
• ASRock B550M/ac Support CD
• 1 x I/O Panel Shield
• 2 x Serial ATA (SATA) Data Cables (Optional)
• 2 x ASRock WiFi 2.4/5 GHz Antennas (Optional)
• 1 x Screw for M.2 Socket (Optional)

1.2 Specifications

Platform

• Micro ATX Form Factor
• Solid Capacitor design
• 2oz Copper PCB

CPU

• Supports 3 ^rd Gen AMD AM4 Ryzen ^™ / future AMD Ryzen ^™ Processors (3000 and 4000 Series Processors)*
  * Not compatible with AMD Ryzen ^™ 5 3400G and Ryzen ^™ 3 3200G.
• Digi Power design
  • 8 Power Phase design

Chipset

- AMD B550

Memory

• Dual Channel DDR4 Memory Technology
- 4 x DDR4 DIMM Slots
- AMD Ryzen series CPUs (Matisse) support DDR4 4533+(OC)/4466(OC)/4400(OC)/4333(OC)/4266(OC)/4200(OC)/4133(OC)/4000(OC)/3866(OC)/3800(OC)/3733(OC)/3600(OC)/3466(OC)/3200/2933/2667/2400/2133 ECC & non-ECC, un-buffered memory*
- AMD Ryzen series APUs (Renoir) support DDR4 4733+ (OC)/4666(OC)/4600(OC)/4533(OC)/4466(OC)/4400(OC)/4333(OC)/4266(OC)/4200(OC)/4133(OC)/4000(OC)/3866(OC)/3800(OC)/3733(OC)/3600(OC)/3466(OC)/3200/2933/2667/2400/2133 ECC & non-ECC, un-buffered memory*

* Please refer to Memory Support List on ASRock's website for more information. (http://www.asrock.com/) * Please refer to page 24 for DDR4 UDIMM maximum frequency support.

• Max. capacity of system memory: 128GB
• Supports Extreme Memory Profile (XMP) memory modules
• 15μ Gold Contact in DIMM Slots

Expansion

AMD Ryzen series CPUs (Matisse)

Slot

- 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3: Gen3 x4 mode)*

AMD Ryzen series APUs (Renoir)

• 2 x PCI Express x16 Slots (PCIE1: Gen3x16 mode; PCIE3: Gen3 x4 mode)*
  * Supports NVMe SSD as boot disks
  • 1 x PCI Express 3.0 x1 Slot
  • Supports AMD Quad CrossFireX ^TM and CrossFireX ^TM
• 1 x M.2 Socket (Key E) with the bundled WiFi-802.11ac module

Graphics

- Integrated AMD Radeon ^TM Vega Series Graphics in Ryzen Series APU*

* Actual support may vary by CPU
- DirectX 12, Pixel Shader 5.0
- Shared memory default 2GB. Max Shared memory supports up to 16GB.

* The Max shared memory 16GB requires 32GB system memory installed.

• Supports HDMI 2.1 with max. resolution up to 4K x 2K (4096x2160) @ 60Hz
• Supports Auto Lip Sync, Deep Color (12bpc), xvYCC and HBR (High Bit Rate Audio) with HDMI 2.1 Port (Compliant HDMI monitor is required)
  • Supports HDR (High Dynamic Range) with HDMI 2.1
  • Supports HDCP 2.3 with HDMI 2.1 Port
• Supports 4K Ultra HD (UHD) playback with HDMI 2.1 Port
  • Supports Microsoft PlayReady®

Audio

• 7.1 CH HD Audio with Content Protection (Realtek ALC1200 Audio Codec)
  • Premium Blu-ray Audio support
  • Supports Surge Protection
  • PCB Isolate Shielding
  • Individual PCB Layers for R/L Audio Channel
• Nahimic Audio

LAN

• PCIE x1 Gigabit LAN 10/100/1000 Mb/s
• Realtek RTL8111H
• Supports Wake-On-LAN
• Supports Lightning/ESD Protection
• Supports Energy Efficient Ethernet 802.3az
- Supports PXE

Wireless

LAN

• Intel® 802.11ac WiFi Module
  • Supports IEEE 802.11a/b/g/n/ac
  • Supports Dual-Band (2.4/5 GHz)
  • Supports high speed wireless connections up to 433Mbps
  • Supports Bluetooth 4.2 + High speed class II

Rear Panel

I/O

• 2 x Antenna Ports
  • 1 x PS/2 Mouse/Keyboard Port
• 1 x HDMI Port
• 4 x USB 3.2 Gen1 Ports (ASMedia ASM1074 hub) (Supports ESD Protection)
  • 2 x USB 2.0 Ports (Supports ESD Protection)
• 1 x RJ-45 LAN Port with LED (ACT/LINK LED and SPEED LED)
  • HD Audio Jacks: Line in / Front Speaker / Microphone

Storage

• 4 x SATA3 6.0 Gb/s Connectors, support RAID (RAID 0, RAID 1 and RAID 10), NCQ, AHCI and Hot Plug
• 1 x Hyper M.2 Socket (M2_1), supports M Key type 2280 M.2 PCI Express module up to Gen4x4 (64 Gb/s) (with Matisse) or Gen3x4 (32 Gb/s) (with Renoir)*

* Supports NVMe SSD as boot disks

* Supports ASRock U.2 Kit

Connector

• 1 x COM Port Header
• 1 x SPI TPM Header
• 1 x Power LED and Speaker Header
- 2 x RGB LED Headers
* Support in total up to 12V/3A, 36W LED Strip

• 2 x Addressable LED Headers
* Support in total up to 5V/3A, 15W LED Strip
• 1 x CPU Fan Connector (4-pin)
* The CPU Fan Connector supports the CPU fan of maximum 1A (12W) fan power.
- 3 x Chassis/Water Pump Fan Connectors (4-pin) (Smart Fan Speed Control)
* The Chassis/Water Pump Fan supports the water cooler fan of maximum 2A (24W) fan power.
* CHA_FAN1/WP, CHA_FAN2/WP and CHA_FAN4/WP can auto detect if 3-pin or 4-pin fan is in use.
• 1 x 24 pin ATX Power Connector
• 1 x 8 pin 12V Power Connector
• 1 x Front Panel Audio Connector
- 2 x USB 2.0 Headers (Support 4 USB 2.0 ports) (Supports ESD Protection)
- 2 x USB 3.2 Gen1 Headers (Support 4 USB 3.2 Gen1 ports) (Supports ESD Protection)

BIOS

Feature

• AMI UEFI Legal BIOS with GUI support
• Supports "Plug and Play"
• ACPI 5.1 compliance wake up events
• Supports jumperfree
- SMBIOS 2.3 support
- CPU, CPU VDDCR_SOC, DRAM, VPPM, +1.8VSB Voltage Multi-adjustment

Hardware

Monitor

• Temperature Sensing: CPU, Chassis/Water Pump Fans
• Fan Tachometer: CPU, Chassis/Water Pump Fans
- Quiet Fan (Auto adjust chassis fan speed by CPU temperature): CPU, Chassis/Water Pump Fans
• Fan Multi-Speed Control: CPU, Chassis/Water Pump Fans
- Voltage monitoring: +12V, +5V, +3.3V, CPU Vcore, CPU VDDCR_SOC, DRAM, VPPM, +1.8V

os

• Microsoft® Windows® 10 64-bit

Certifica-

- FCC, CE

tions

- ErP/EuP ready (ErP/EuP ready power supply is required)

* For detailed product information, please visit our website: http://www.asrock.com

Please realize that there is a certain risk involved with overclocking, including adjusting the setting in the BIOS, applying Untied Overclocking Technology, or using third-party overclocking tools. Overclocking may affect your system's stability, or even cause damage to the components and devices of your system. It should be done at your own risk and expense. We are not responsible for possible damage caused by overclocking.

Chapter 2 Installation

This is a Micro ATX form factor motherboard. Before you install the motherboard, study the configuration of your chassis to ensure that the motherboard fits into it.

Pre-installation Precautions

Take note of the following precautions before you install motherboard components or change any motherboard settings.

• Make sure to unplug the power cord before installing or removing the motherboard. Failure to do so may cause physical injuries to you and damages to motherboard components.
• In order to avoid damage from static electricity to the motherboard's components, NEVER place your motherboard directly on a carpet. Also remember to use a grounded wrist strap or touch a safety grounded object before you handle the components.
• Hold components by the edges and do not touch the ICs.
• Whenever you uninstall any components, place them on a grounded anti-static pad or in the bag that comes with the components.
• When placing screws to secure the motherboard to the chassis, please do not over-tighten the screws! Doing so may damage the motherboard.

2.1 Installing the CPU

Unplug all power cables before installing the CPU.

1

Diagram of a square electronic device with a central square and antenna, showing an orange curved arrow indicating rotation or movement (no text or symbols present)

2

Technical line drawing of a mechanical component with a highlighted circular feature (no text or symbols)

3

Diagram of a rectangular device with a curved arrow indicating rotation or movement (no text or symbols)

2.2 Installing the CPU Fan and Heatsink

After you install the CPU into this motherboard, it is necessary to install a larger heatsink and cooling fan to dissipate heat. You also need to spray thermal grease between the CPU and the heatsink to improve heat dissipation. Make sure that the CPU and the heatsink are securely fastened and in good contact with each other.

Please turn off the power or remove the power cord before changing a CPU or heatsink.

Installing the CPU Box Cooler SR1

1

Technical diagram showing screw installation on a microchip base (no text or symbols)

2

Technical line drawing of an electronic component with two housing parts and orange arrows indicating assembly or movement (no text or symbols)

3

Technical diagram showing assembly of an accelerometer with labeled components and directional arrows indicating assembly steps.

4

Technical line drawing of a mechanical device with mounting base and wiring, no visible text or symbols

Installing the AM4 Box Cooler SR2

1

Technical diagram showing screw fasteners inserted into a microchip assembly (no text or labels)

2

Technical line drawing of an electronic component with two views and orange arrows indicating assembly or force (no text or symbols present)

3

Technical diagram of a mechanical assembly with exploded view and mounting base (no text or symbols)

4

Technical line drawing of a mechanical device with mounting base and wiring, no visible text or symbols

*The diagrams shown here are for reference only. The headers might be in a different position on your motherboard.

Installing the AM4 Box Cooler SR3

1

Technical line drawing of a mechanical assembly with a central component and two supporting components (no text or symbols)

2

Technical line drawing of a mechanical device with no visible text or symbols

3

Technical line drawing of a mechanical device with no visible text or symbols

4

Technical line drawing of a mechanical device with internal components and a highlighted orange section (no text or symbols)

5

Technical line drawing of a mechanical device with internal components and wiring (no text or symbols)

6

+12V +12V

*The diagrams shown here are for reference only. The headers might be in a different position on your motherboard.

2.3 Installing Memory Modules (DIMM)

This motherboard provides four 288-pin DDR4 (Double Data Rate 4) DIMM slots, and supports Dual Channel Memory Technology.

1. For dual channel configuration, you always need to install identical (the same brand, speed, size and chip-type) DDR4 DIMM pairs.
2. It is unable to activate Dual Channel Memory Technology with only one or three memory module installed.
3. It is not allowed to install a DDR, DDR2 or DDR3 memory module into a DDR4 slot; otherwise, this motherboard and DIMM may be damaged.
4. We suggest that you install the memory modules on DDR4_A2 and DDR4_B2 first for better DRAM compatibility on 2 DIMMs configuration.

AMD non-XMP Memory Frequency Support

Ryzen Series CPUs (Matisse):

UDIMM Memory Slot

A1 A2 B1 B2

Frequency

(Mhz)

- SR -- 3200

- DR -- 3200

- SR - SR 3200

- DR - DR 3200

SR SR SR SR 2933

SR/DR DR SR/DR DR 2667

SR/DR SR/DR SR/DR SR/DR 2667

Ryzen Series APUs (Renoir):

UDIMM Memory SlotA1 A2 B1 B2

Frequency(Mhz)

- SR -- 3200

- DR - - 3200

- SR - SR 3200

- DR - DR 3200

SR SR SR SR 2933

SR/DR DR SR/DR DR 2667

SR/DR SR/DR SR/DR SR/DR 2667

SR: Single rank DIMM, 1Rx4 or 1Rx8 on DIMM module label

DR: Dual rank DIMM, 2Rx4 or 2Rx8 on DIMM module label

The DIMM only fits in one correct orientation. It will cause permanent damage to the motherboard and the DIMM if you force the DIMM into the slot at incorrect orientation.

1

Technical line drawing of a mechanical support structure with an arrow indicating rotation (no text or symbols)

2

Illustration of hands installing a mechanical component with a highlighted section (no text or symbols)

3

Isometric line drawing of a rectangular electronic component with multiple square slots and a curved arrow indicating rotation (no text or symbols)

2.4 Expansion Slots (PCI Express Slots)

There are 3 PCI Express slots on the motherboard.

Before installing an expansion card, please make sure that the power supply is switched off or the power cord is unplugged. Please read the documentation of the expansion card and make necessary hardware settings for the card before you start the installation.

PCIe slots:

PCIE1 (PCIe 4.0 x16 slot) is used for PCI Express x16 lane width graphics cards. PCIE2 (PCIe 3.0 x1 slot) is used for PCI Express x1 lane width cards. PCIE3 (PCIe 3.0 x16 slot) is used for PCI Express x4 lane width graphics cards.

PCIe Slot Configurations

	PCIE1	PCIE2	PCIE3
Ryzen Series CPUs (Matisse)	Gen4x16	Gen3x1	Gen3x4
Ryzen Series CPUs (Renoir)	Gen3x16	Gen3x1	Gen3x4

For a better thermal environment, please connect a chassis fan to the motherboard's chassis fan connector (CHA_FAN1/WP, CHA_FAN2/WP, CHA_FAN3/WP or CHA_FAN4/WP) when using multiple graphics cards.

2.5 Jumpers Setup

The illustration shows how jumpers are setup. When the jumper cap is placed on the pins, the jumper is “Short”. If no jumper cap is placed on the pins, the jumper is “Open”.

Short

Open

Clear CMOS Jumper

(CLRCMOS1)

(see p.1, No. 21)

2-pin Jumper

Short: Clear CMOS

Open: Default

CLRCMOS1 allows you to clear the data in CMOS. The data in CMOS includes system setup information such as system password, date, time, and system setup parameters. To clear and reset the system parameters to default setup, please turn off the computer and unplug the power cord, then use a jumper cap to short the pins on CLRCMOS1 for 3 seconds. Please remember to remove the jumper cap after clearing the CMOS. If you need to clear the CMOS when you just finish updating the BIOS, you must boot up the system first, and then shut it down before you do the clear-CMOS action.

2.6 Onboard Headers and Connectors

Onboard headers and connectors are NOT jumpers. Do NOT place jumper caps over these headers and connectors. Placing jumper caps over the headers and connectors will cause permanent damage to the motherboard.

System Panel Header (9-pin PANEL1) (see p.1, No. 12)

PLED+ PLED- PWRBTN# GND 1 GND RESET# GND HDLED- HDLED+

Connect the power button, reset button and system status indicator on the chassis to this header according to the pin assignments below. Note the positive and negative pins before connecting the cables.

PWRBTN (Power Button):

Connect to the power button on the chassis front panel. You may configure the way to turn off your system using the power button.

RESET (Reset Button):

Connect to the reset button on the chassis front panel. Press the reset button to restart the computer if the computer freezes and fails to perform a normal restart.

PLED (System Power LED):

Connect to the power status indicator on the chassis front panel. The LED is on when the system is operating. The LED keeps blinking when the system is in S1/S3 sleep state. The LED is off when the system is in S4 sleep state or powered off (S5).

HDLED (Hard Drive Activity LED):

Connect to the hard drive activity LED on the chassis front panel. The LED is on when the hard drive is reading or writing data.

The front panel design may differ by chassis. A front panel module mainly consists of power button, reset button, power LED, hard drive activity LED, speaker and etc. When connecting your chassis front panel module to this header, make sure the wire assignments and the pin assignments are matched correctly.

Power LED and Speaker Header

(7-pin SPK_PLED1)

(see p.1, No. 13)

Please connect the chassis power LED and the chassis speaker to this header.

Serial ATA3 Connectors

(SATA3_1:

see p.1, No. 9)

(SATA3_2:

see p.1, No. 10)

(SATA3_3:

see p.1, No. 11)(Lower)

(SATA3_4:

see p.1, No. 11)(Upper)

SATA3_4 SATA3_1 SATA3_3 SATA3_2

These four SATA3 connectors support SATA data cables for internal storage devices with up to 6.0 Gb/s data transfer rate.

USB 2.0 Headers

(9-pin USB_3_4)

(see p.1, No. 18)

(9-pin USB_5_6)

(see p.1, No. 19)

USB_PWR P- P+ GND DUMMY 1 P- P+ GND USB_PWR

There are two headers on this motherboard. Each USB 2.0 header can support two ports.

USB 3.2 Gen1 Headers

(19-pin F_USB3_1_2)

(see p.1, No. 8)

There are two headers on this motherboard. Each USB 3.2 Gen1 header can support two ports.

(19-pin F_USB3_3_4)

(see p.1, No. 14)

IntA_P_D+ IntA_P_D- GND IntA_P_SSTX+ IntA_P_SSTX- GND IntA_P_SSRX+ IntA_P_SSRX- Vbus Vbus IntA_P_SSRX- GND IntA_P_SSTX- GND IntA_P_SSTX+ IntA_P_D- D

Front Panel Audio Header (9-pin HD_AUDIO1) (see p.1, No. 25)

GND PRESENCE# MIC_RET OUT_RET 1 J_SENSE OUT2_R MIC2_R MIC2_L

This header is for connecting audio devices to the front audio panel.

1. High Definition Audio supports Jack Sensing, but the panel wire on the chassis must support HDA to function correctly. Please follow the instructions in our manual and chassis manual to install your system.
2. If you use an AC'97 audio panel, please install it to the front panel audio header by the steps below:

A. Connect Mic_IN (MIC) to MIC2_L.
B. Connect Audio_R (RIN) to OUT2_R and Audio_L (LIN) to OUT2_L.
C. Connect Ground (GND) to Ground (GND).
D. MIC_RET and OUT_RET are for the HD audio panel only. You don't need to connect them for the AC'97 audio panel.
E. To activate the front mic, go to the "FrontMic" Tab in the Realtek Control panel and adjust "Recording Volume".

Chassis Water Pump Fan Connectors

(4-pin CHA_FAN1/WP)

(see p.1, No. 26)

This motherboard provides three 4-Pin water cooling chassis fan connectors. If you plan to connect a 3-Pin chassis water cooler fan, please connect it to Pin 1-3.

(4-pin CHA_FAN2/WP)

(see p.1, No. 20)

(4-pin CHA_FAN4/WP)

(see p.1, No. 15)

GND FAN_VOLTAGE FAN_SPEED FAN_SPEED_CONTROL 1 2 3 4

CPU Fan Connector (4-pin CPU_FAN1) (see p.1, No. 2)

This motherboard provides a 4-Pin CPU fan (Quiet Fan) connector. If you plan to connect a 3-Pin CPU fan, please connect it to Pin 1-3.

ATX Power Connector (24-pin ATXPWR1) (see p.1, No. 7)

This motherboard provides a 24-pin ATX power connector. To use a 20-pin ATX power supply, please plug it along Pin 1 and Pin 13.

ATX 12V Power Connector (8-pin ATX12V1) (see p.1, No. 1)

This motherboard provides an 8-pin ATX 12V power connector. To use a 4-pin ATX power supply, please plug it along Pin 1 and Pin 5. *Warning: Please make sure that the power cable connected is for the CPU and not the graphics card. Do not plug the PCIe power cable to this connector.

Serial Port Header (9-pin COM1) (see p.1, No. 22)

RRXD1 DDTR#1 DDSR#1 CCTS#1 RRI#1 RRTS#1 GND TTXD1 DDCD#1

This COM1 header supports a serial port module.

SPI TPM Header (13-pin SPI_TPM_J1) (see p.1, No. 17)

SPI_DQ3 +3.3V Dummy CLK SPI_MOSI RST# TPM_PIRQ 1 SPI_TPM_CS# GND RSMRST# SPI_MISO SPI_CSO SPI_DQ2

This connector supports SPI Trusted Platform Module (TPM) system, which can securely store keys, digital certificates, passwords, and data. A TPM system also helps enhance network security, protects digital identities, and ensures platform integrity.

RGB LED Headers (4-pin RGB_LED1) (see p.1, No. 5)

These two RGB headers are used to connect RGB LED extension cable which allows users to choose from various LED lighting effects.

(4-pin RGB_LED2) (see p.1, No. 23)

Caution: Never install the RGB LED cable in the wrong orientation; otherwise, the cable may be damaged.

*Please refer to page 39 for further instructions on these two headers.

Addressable LED Headers

(3-pin ADDR_LED1)

(see p.1, No. 6)

(3-pin ADDR_LED2)

(see p.1, No. 24)

These two Addressable headers are used to connect Addressable LED extension cable which allows users to choose from various LED lighting effects.

Caution: Never install the Addressable LED cable in the wrong orientation; otherwise, the cable may be damaged.

*Please refer to page 40 for further instructions on this header.

2.7 Post Status Checker

Post Status Checker (PSC) diagnoses the computer when users power on the machine. It emits a red light to indicate whether the CPU, memory, VGA or storage is dysfunctional. The lights go off if the four mentioned above are functioning normally.

2.8 M.2\_SSD (NGFF) Module Installation Guide (M2\_1)

The M.2, also known as the Next Generation Form Factor (NGFF), is a small size and versatile card edge connector that aims to replace mPCIe and mSATA.

The Hyper M.2 Socket (M2_1) supports M Key type 2280 M.2 PCI Express module up to Gen4x4 (64 Gb/s) (with Matisse) or Gen3x4 (32 Gb/s) (with Renoir).

Installing the M.2\_SSD (NGFF) Module

Pure technical line drawing of a rectangular component with notches and side brackets (no text or symbols)

Step 1

Prepare a M.2_SSD (NGFF) module and the screw.

Technical line drawing of a mechanical component with dimension lines and labeled section A (no text or symbols beyond labels)

Step 2

Depending on the PCB type and length of your M.2_SSD (NGFF) module, find the corresponding nut location to be used.

No. 1

Nut Location A

PCB Length 8cm

Module Type Type2280

Technical diagram of a mechanical assembly with a lever and pivot, showing no text or symbols

A 20°

Step 3

Align and gently insert the M.2

(NGFF) SSD module into the M.2

slot. Please be aware that the M.2

(NGFF) SSD module only fits in one orientation.

Pure technical diagram showing a mechanical setup with a spring and lever, no text or symbols present

Step 4

Tighten the screw with a screwdriver to secure the module into place.

Please do not overtighten the screw as this might damage the module.

M.2\_SSD (NGFF) Module Support List (M2\_1)

Vendor Interface P/N
ADATA PCIe3 x4 ASX7000NP-128GT-C
ADATA PCIe3 x4 ASX8000NP-256GM-C
ADATA PCIe3 x4 ASX7000NP-256GT-C
ADATA PCIe3 x4 ASX8000NP-512GM-C
ADATA PCIe3 x4 ASX7000NP-512GT-C
Apacer PCIe3 x4 AP240GZ280
Corsair PCIe3 x4 CSSD-F240GBMP500
Intel PCIe3 x4 SSDPEKKF256G7
Intel PCIe3 x4 SSDPEKKF512G7
Kingston PCIe3 x4 SKC1000/480G
Kingston PCIe2 x4 SH2280S3/480G
OCZ PCIe3 x4 RVD400 -M2280-512G (NVME)
PATR IOT PCIe3 x4 PH240GPM280SSDR NVME
Plextor PCIe3 x4 PX-128M8PeG
Plextor PCIe3 x4 PX-1TM8PeG
Plextor PCIe3 x4 PX-256M8PeG
Plextor PCIe3 x4 PX-512M8PeG
Plextor PCIe	PX-G256M6e
Plextor PCIe	PX-G512M6e
Samsung	PCIe3 x4	SM961 MZVPW128HEGM (NVM)
Samsung	PCIe3 x4	PM961 MZVLW128HEGR (NVME)
Samsung	PCIe3 x4	960 EVO (MZ-V6E250) (NVME)
Samsung	PCIe3 x4	960 EVO (MZ-V6E250BW) (NVME)
Samsung	PCIe3 x4 SM951 (NVME)
Samsung	PCIe3 x4	SM951 (MZHPV256HDGL)
Samsung	PCIe3 x4	SM951 (MZHPV512HDGL)
Samsung	PCIe3 x4 SM951 (NVME)
Samsung	PCIe x4	XP941-512G (MZHPU512HCGL)
SanDisk	PCIe	SD6PP4M-128G
SanDisk	PCIe	SD6PP4M-256G
TEAM	PCIe3 x4 TM8FP2240G0C101
TEAM	PCIe3 x4 TM8FP2480GC110
WD	PCIe3 x4	WDS256G1X0C-00ENX0 (NVME)
WD	PCIe3 x4	WDS512G1X0C-00ENX0 (NVME)

For the latest updates of M.2_SSD (NFGG) module support list, please visit our website for details: http://www.asrock.com

2.9 ASRock Polychrome SYNC

ASRock Polychrome SYNC is a lighting control utility specifically designed for unique individuals with sophisticated tastes to build their own stylish colorful lighting system. Simply by connecting the LED strip, you can customize various lighting schemes and patterns, including Static, Breathing, Strobe, Cycling, Music, Wave and more.

Connecting the LED Strip

Connect your RGB LED strips to the RGB LED Headers (RGB_LED1, RGB_LED2) on the motherboard.

ISRock 8550M/3C RGB_LED1 B R G 12V 1 RGB_LED2 1 12VG R B

1. Never install the RGB LED cable in the wrong orientation; otherwise, the cable may be damaged.
2. Before installing or removing your RGB LED cable, please power off your system and unplug the power cord from the power supply. Failure to do so may cause damages to motherboard components.

1. Please note that the RGB LED strips do not come with the package.
2. The RGB LED header supports standard 5050 RGB LED strip (12V/G/R/B), with a maximum power rating of 3A (12V) and length within 2 meters.

Connecting the Addressable RGB LED Strip

Connect your Addressable RGB LED strips to the Addressable LED Headers (ADDR_LED1, ADDR_LED2) on the motherboard.

ASRock BS50M/AC ADDR_LED1 VOUT DO_ADDR GND ADDR_LED2 1 1 GND DO_ADDR VOUT

1. Never install the RGB LED cable in the wrong orientation; otherwise, the cable may be damaged.
2. Before installing or removing your RGB LED cable, please power off your system and unplug the power cord from the power supply. Failure to do so may cause damages to motherboard components.

1. Please note that the RGB LED strips do not come with the package.
2. The RGB LED header supports WS2812B addressable RGB LED strip (5V/Data/GND), with a maximum power rating of 3A (5V) and length within 2 meters.

ASRock Polychrome SYNC Utility

Now you can adjust the RGB LED color through the ASRock Polychrome SYNC Utility. Download this utility from the ASRock Live Update & APP Shop and start coloring your PC style your way!

Drag the tab to customize your preference. LED Channel: Chipset Heatsink Select a RGB LED light effect from the drop-down menu. Toggle on/off the RGB LED switch Style Static Static Breathing Stroke Cycling Random Random Cycling Music Wave Sync RGB LED effects for all LED regions of the motherboard Apply All

1 Einleitung

Short Open

(4-polig, CHA_FAN1/WP)

Embases USB 3.2 Gen1

• Supporta "Plug and Play"

• Supporta jumperfree

- Monitoraggio tensione: +12V, +5V, +3.3V, CPU Vcore, CPU VDDCR_SOC, DRAM, VPPM, +1.8V

so

- Microsoft® Windows® 10 64 bit

Certificazioni

- FCC, CE

(CHA_FAN1/WP a 4 pin)

Apagar o Jumper CMOS (CLRCMOS1)

(ver p.1, N.° 21)

Jumper de 2 pinos

Curto: Apagar CMOS

Abrir: Padrão

- Obsługa "Plug and Play"

- 전압 모니터링 : +12V, +5V, +3.3V, CPU Vcore, CPU VDDCR_SOC, DRAM, VPPM, +1.8V

os

If you need to contact ASRock or want to know more about ASRock, you're welcome to visit ASRock's website at http://www.asrock.com; or you may contact your dealer for further information. For technical questions, please submit a support request form at https://event.asrock.com/tsd.asp

ASRock Incorporation

2F., No.37, Sec. 2, Jhongyang S. Rd., Beitou District,

Taipei City 112, Taiwan (R.O.C.)

ASRock EUROPE B.V.

Bijsterhuizen 11-11

6546 AR Nijmegen

The Netherlands

Phone: [phone]

Fax: [phone]

ASRock America, Inc.

13848 Magnolia Ave, Chino, CA91710

U.S.A.

Phone: [phone]

Fax: [phone]

DECLARATION OF CONFORMITY

Per FCC Part 2 Section 2.1077(a)

Responsible Party Name: ASRock Incorporation

Address: 13848 Magnolia Ave, Chino, CA91710

Phone/Fax N o: [phone]/[phone]

hereby declares that the product

Product Name : Motherboard

Model Number : B550M/ac

Conforms to the following specifications:

☒ FCC Part 15, Subpart B, Unintentional Radiators

Supplementary Information:

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Representative Person's Name: James

Signature :

Date : May 12, 2017

EU Declaration of Conformity

ASRock

For the following equipment:

Motherboard

(Product Name)

B550M/ac / ASRock

(Model Designation / Trade Name)

ASRock Incorporation

(Manufacturer Name)

2F., No.37, Sec. 2, Jhongyang S. Rd., Beitou District, Taipei City 112, Taiwan (R.O.C.)

(Manufacturer Address)

☒ EMC — Directive 2014/30/EU (from April 20th, 2016)

□ EN 55022:2010/AC:2011 Class B

EN 55024:2010/A1:2015

EN 55032:2012+AC:2013 Class B

EN 61000-3-3:2013

EN 61000-3-2:2014

RED-Directive 2014/53/EU

□ EN 300 328 V2.1.1 EN 301 489-17 V3.1.1

×

□ EN 301 893 V2.1.1

□ EN 301 489-3 V2.1.1

□ EN 300 220 V3.1.1

□LVD — Directive 2014/35/EU (from April 20th, 2016)

□ EN 60950-1:2011+ A2:2013

□ EN 60950-1:2006/A12:2011

☒ RoHS — Directive 2011/65/EU

CE marking

CE

(EU conformity marking)

ASRock EUROPE B.V.

(Company Name)

Bijsterhuizen 1111 6546 AR Nijmegen The Netherlands

(Company Address)

Person responsible for making this declaration:

(Name, Surname)

A.V.P

(Position / Title)

August 21, 2020

(Date)

P/N: 15G062246000AK V1.0