Asrock B550M/ac Quick Installation Guide

Version 1.0
Published May 2020
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 identication or explanation and to the owners’ benet, without intent to

infringe.

Disclaimer:

Specications 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 tness for a particular
purpose.

In no event shall ASRock, its directors, ocers, employees, or agents be liable for
any indirect, special, incidental, or consequential damages (including damages for
loss of prots, 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.

is 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

e 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)

e terms HDMI® and HDMI High-Denition Multimedia Interface, and the
HDMI logo are trademarks or registered trademarks of HDMI Licensing LLC in the
United States and other countries.

CE Warning

is device complies with directive 2014/53/EU issued by the Commision of the European
Community.

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

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

Bluetooth 2400-2483.5 MHz 8.5 + / -1.5 dbm

5250-5350 MHz

5470-5725 MHz

18.5 + / -1.5 dbm (no TPC)

21.5 + / -1.5 dbm (TPC)

25.5 + / -1.5 dbm (no TPC)

28.5 + / -1.5 dbm (TPC)

3

4

10

11

1

ATXP WR1

Sup er

I/O

CLRCMOS1

1

PCIE1

HD_AUDIO1

1

SOCKETAM4

F_USB3 _1_2

1

CHA_FAN1/WP

1

RoHS

SPK_PLED1

1

DDR 4_A1 (6 4 bit, 288 -pin mo dule)

DDR 4_A2 (6 4 bit, 288 -pin mo dule)

DDR 4_B1 (6 4 bit, 288 -pin mo dule)

DDR 4_B2 (6 4 bit, 288 -pin mo dule)

PCIE2

PCIE3

HDLED RESET

PLED PWRBTN

PANEL1

M2_1

AMD

Promontory

B550

1

USB_3_4

19

26

CPU_FAN1

CHA_FAN4/WP

1

USB_5_6

24

23

25

ATX12V1

2

ADDR_LED1

1

1

RGB_LED1

6

5

SATA3_1

SATA3_2

9

1

SPI_TPM_J1

1

F_USB3_3_4

20

CHA_FAN2
/WP

RGB_LED2

1

ADDR_LED2

1

CMOS

Battery

LAN

AUDIO
CODEC

22

17

CPU

DRAM

VGA

BOOT

16

M2_3

NUT1

1

COM1

21

B5 50 M /a c

Top:

LINE IN

Center :

FRONT

Bottom :

MIC IN

RJ- 45 LAN

USB 3.2 Gen1
T: USB3
B: USB4

USB 3.2 Gen1
T: USB1
B: USB2

USB 2.0
T: USB1
B: USB2

PS2

Keyboard/

Mouse

HDM I1

WiFi-802.11ac

Module

SATA3_4

SATA3_3

Motherboard Layout

B550M/ac

7

8

12

13

14

15

English

18

1

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)

English

2

I/O Panel

B550M/ac

3

1 2 4

10

6789

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 por ts consume DUAL
Power (+5VDUAL). e USB_ 2 is optimal for connecting the USB Type speake r and headset .

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

ACT/LINK LED

SPEED LED

LAN Por t

Activity / Link LED Speed LED

Status Description Status Description

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

5

English

3

*** Function of the Audio Ports in 7.1-channel Conguration:

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

English

4

B550M/ac

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

WiFi-802.11ac + BT Module

is motherboard comes with an exclusive WiFi 802.11 a/b/g/n/ac + BT v4.2 module
that oers 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.
* e transmission speed may vary according to the environment.

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5

WiFi Antennas Installation Guide

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.

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6

Chapter 1 Introduction

ank 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.

Becau se the motherboard specications and the BIOS soware might be updated, the
content of this documentation will be subject to change without notice. In case any modi­cations of this documentation occur, the updated version will be available on ASRock’s
website w ithout further notice. If you require technical support related to this mother­board, please visit our website for specic information about the model you are using. You
may nd the l atest VGA cards and CPU suppor t list on ASRock’s website a s 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)

•

B550M/ac

English

7

English

1.2 Specications

Platform

CPU

Chipset

Memory

•

•

•

•

* Not compatible with AMD Ryzen™ 5 3400G and Ryzen™ 3
3200G.

•

•

•

•

•

•

•

* 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.

•

•

•

Micro ATX Form Factor
Solid Capacitor design
2oz Copper PCB

Supports 3rd Gen AMD AM4 Ryzen™ / future AMD Ryzen™
Processors (3000 and 4000 Series Processors)*

Digi Power design
8 Power Phase design

AMD B550

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-buered 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, un­buered memory*

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

Expansion
Slot

AMD Ryzen series CPUs (Matisse)

2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3:

•

Gen3 x4 mode)*

8

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 CrossFireXTM and CrossFireX

•

1 x M.2 Socket (Key E) with the bundled WiFi-802.11ac

•

module

B550M/ac

TM

Graphics

Audio

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.
* e 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 Microso PlayReady®

•

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

•

English

9

LAN

Wireless
LAN

Rear Panel
I/O

Storage

PCIE x1 Gigabit LAN 10/100/1000 Mb/s

•

Realtek RTL8111H

•

Supports Wake-On-LAN

•

Supports Lightning/ESD Protection

•

Supports Energy Ecient Ethernet 802.3az

•

Supports PXE

•

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

•

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

•

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

English

10

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

BIOS
Feature

2 x Addressable LED Headers

•

* Support in total up to 5V/3A, 15W LED Strip

1 x CPU Fan Connector (4-pin)

•

* e 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)
* e 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)

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

B550M/ac

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

English

11

Microso® Windows® 10 64-bit

OS

Certica­tions

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

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

•

FCC, CE

•

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

•

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12

Chapter 2 Installation

is is a Micro ATX form factor motherboard. Before you install the motherboard,
study the conguration of your chassis to ensure that the motherboard ts 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.

B550M/ac

13

English

2.1 Installing the CPU

Unplug all power cables be fore installing the CPU.

1

English

14

2

B550M/ac

3

15

English

2.2 Installing the CPU Fan and Heatsink

Aer 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 o the power or remove the power cord before changing a CPU or heatsink.

Installing the CPU Box Cooler SR1

1

English

16

2

B550M/ac

3

4

1

N

FA

_

U

P

C

English

17

Installing the AM4 Box Cooler SR2

1

2

English

18

B550M/ac

3

19

English

4

1
N

FA

_

U

P

C

*e diagrams shown here are for reference only. e headers might be in a dierent position on
your motherboard.

English

20

Installing the AM4 Box Cooler SR3

1

B550M/ac

2

English

21

3

4

English

22

B550M/ac

5

FAN1

CPU_

6

1

N

FA

_

U

P

C

2
D

E

L

_

B

RG

+12V

*e diagrams shown here are for reference only. e headers might be in a dierent position
on your motherboard.

English

23

2.3 Installing Memory Modules (DIMM)

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

1. For dual channel conguration , you always need to in stall identical (the same
brand, speed , size and chip-type) DDR4 DIMM pairs.

2. It is unable to activate Du al 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_A 2 and DDR4_B2 rst
for better DRAM compatibility on 2 DIMM s conguration.

AMD non-XMP Memory Frequency Support

Ryzen Series CPUs (Matisse):

English

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

24

Ryzen Series APUs (Renoir):

B550M/ac

UDIMM Memory Slot

A1 A2 B1 B2

- 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 2R x8 on DIMM module label

Frequency

(Mhz)

25

English

e DIMM only ts in one correct orientation. It will cause permanent damage to
the motherboard and the DIMM if you force the DIMM into the slot at incor rect
orientation.

1

2

English

26

3