Asus Pro B660M-C D4 User manual

Motherboard
Pro B660M-C D4

ii
E19940
Revised Edition V2
February 2022
Copyright © 2022 ASUSTeK COMPUTER INC. All Rights Reserved.
No part of this manual, including the products and software described in it, may be reproduced,
transmitted, transcribed, stored in a retrieval system, or translated into any language in any form or by any
means, except documentation kept by the purchaser for backup purposes, without the express written
permission of ASUSTeK COMPUTER INC. (“ASUS”).
Product warranty or service will not be extended if: (1) the product is repaired, modied or altered, unless
such repair, modication of alteration is authorized in writing by ASUS; or (2) the serial number of the
product is defaced or missing.
ASUS PROVIDES THIS MANUAL “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL ASUS, 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 USE OR DATA, INTERRUPTION OF BUSINESS AND THE LIKE),
EVEN IF ASUS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES ARISING FROM ANY
DEFECT OR ERROR IN THIS MANUAL OR PRODUCT.
SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FURNISHED FOR
INFORMATIONAL USE ONLY, AND ARE SUBJECT TO CHANGE AT ANY TIME WITHOUT NOTICE,
AND SHOULD NOT BE CONSTRUED AS A COMMITMENT BY ASUS. ASUS ASSUMES NO
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Products and corporate names appearing in this manual may or may not be registered trademarks or
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owners’ benet, without intent to infringe.

iii
Contents
Safety information...................................................................................................... iv
About this guide.......................................................................................................... v
Package contents....................................................................................................... vi
Pro B660M-C D4 specications summary ............................................................... vi
Chapter 1 Product Introduction
1.1 Before you proceed...................................................................................... 1-1
1.2 Motherboard overview ................................................................................. 1-1
1.3 Central Processing Unit (CPU).................................................................... 1-8
1.4 System memory.......................................................................................... 1-10
Chapter 2 BIOS and RAID Support
2.1 BIOS setup program..................................................................................... 2-1
2.2 BIOS menu screen........................................................................................ 2-2
2.3 Event Log ...................................................................................................... 2-3
2.4 Exit menu ...................................................................................................... 2-4
2.5 RAID congurations..................................................................................... 2-5
Appendix
Warranty................................................................................................................... A-6
ASUS contact information...................................................................................... A-8
Service and Support ............................................................................................... A-8

iv
Safety information
Electrical safety
• To prevent electrical shock hazard, disconnect the power cable from the electrical outlet
before relocating the system.
• When adding or removing devices to or from the system, ensure that the power cables
for the devices are unplugged before the signal cables are connected. If possible,
disconnect all power cables from the existing system before you add a device.
• Before connecting or removing signal cables from the motherboard, ensure that all power
cables are unplugged.
• Seek professional assistance before using an adapter or extension cord. These devices
could interrupt the grounding circuit.
• Ensure that your power supply is set to the correct voltage in your area. If you are not
sure about the voltage of the electrical outlet you are using, contact your local power
company.
• If the power supply is broken, do not try to x it by yourself. Contact a qualied service
technician or your retailer.
Operation safety
• Before installing the motherboard and adding components, carefully read all the manuals
that came with the package.
• Before using the product, ensure all cables are correctly connected and the power cables
are not damaged. If you detect any damage, contact your dealer immediately.
• To avoid short circuits, keep paper clips, screws, and staples away from connectors,
slots, sockets and circuitry.
• Avoid dust, humidity, and temperature extremes. Do not place the product in any area
where it may be exposed to moisture.
• Place the product on a stable surface.
• If you encounter technical problems with the product, contact a qualied service
technician or your retailer.
• Your motherboard should only be used in environments with ambient temperatures
between 0°C and 40°C.

v
About this guide
This user guide contains the information you need when installing and conguring the
motherboard.
How this guide is organized
This guide contains the following parts:
• Chapter 1: Product Introduction
This chapter describes the features of the motherboard and the new technology it
supports. It includes descriptions of the switches, jumpers, and connectors on the
motherboard.
• Chapter 2: BIOS and RAID Support
This chapter tells how to boot into the BIOS and support RAID.
Where to nd more information
Refer to the following sources for additional information and for product and software
updates.
1. ASUS website
The ASUS website provides updated information on ASUS hardware and software
products. Refer to the ASUS contact information.
2. Optional documentation
Your product package may include optional documentation, such as warranty flyers,
that may have been added by your dealer. These documents are not part of the
standard package.
Conventions used in this guide
To ensure that you perform certain tasks properly, take note of the following symbols used
throughout this manual.
CAUTION: Information to prevent damage to the components and injuries to yourself when
trying to complete a task.
IMPORTANT: Instructions that you MUST follow to complete a task.
NOTE: Tips and additional information to help you complete a task.

vi
Pro B660M-C D4 specications summary
CPU
Intel®Socket LGA1700 for 12th Gen Intel®Core™, Pentium®Gold and
Celeron®Processors*
Supports Intel®Turbo Boost Technology 2.0 and Intel®Turbo Boost Max
Technology 3.0**
* Refer to www.asus.com for CPU support list.
** Intel®Turbo Boost Max Technology 3.0 support depends on the CPU types.
Chipset Intel®B660 Chipset
Memory
4 x DIMM, Max. 128GB, DDR4 4600(OC)/4400(OC)/4266(OC)/4000(OC)/
3733(OC)/3600(OC)/3466(OC)/3400(OC)/
3333(OC)/3200/3000/2933/2800/2666/2400/2133 Non-ECC, Un-buffered
Memory*
Dual Channel Memory Architecture
Supports Intel® Extreme Memory Prole (XMP)
OptiMem
* Actual Memory data rate depends on the CPU types and DRAM modules, for more
information refer to www.asus.com for the Memory QVL (Qualied Vendors Lists).
Graphics
2 x DisplayPort**
1 x D-Sub port
1 x HDMI® port***
* Graphics specications may vary between CPU types. Please refer to www.intel.
com for any updates.
** Supports max. 4K@60Hz as specied in DisplayPort 1.4.
*** Supports 4K@60Hz as specied in HDMI 2.1.
Expansion Slots
Intel®12th Gen Processors
1 x PCIe 4.0/3.0 x16 slot
Intel®B660 Chipset
2 x PCIe 3.0 x1 slots
(continued on the next page)
Package contents
Check your motherboard package for the following items.
Motherboard 1 x Pro B660M-C D4 motherboard
Cables 2 x SATA 6Gb/s cables
Miscellaneous
1 x I/O Shield
1 x M.2 SSD screw package
1 x M.2 Key E screw package
Installation Media 1 x Support DVD
Documentation 1 x ACC Express Activation Key Card
1 x User guide
If any of the above items is damaged or missing, contact your retailer.

vii
Pro B660M-C D4 specications summary
Storage
Total supports 2 x M.2 slots and 4 x SATA 6Gb/s ports*
Intel®12th Gen Processors
M.2_1 slot (Key M), type 2242/2260/2280
- Intel®12th Gen processors support PCIe 4.0 x4 mode
Intel®B660 Chipset**
M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4)
4 x SATA 6Gb/s ports
*Intel®Rapid Storage Technology supports SATA RAID 0/1/5/10.
**Intel®Rapid Storage Technology supports Intel®Optane Memory H Series on
PCH attached M.2 slots.
Ethernet 1 x Intel®1Gb Ethernet
ASUS LANGuard
Wireless & Bluetooth M.2 slot only (Key E, CNVi & PCIe interface)*
*Wi-Fi module is sold separately.
USB
Rear USB (Total 4 ports)
2 x USB 3.2 Gen 1 ports (2 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
Front USB (Total 7 ports)
1 x USB 3.2 Gen 1 connector (supports USB Type-C®)
1 x USB 3.2 Gen 1 header supports additional 2 USB 3.2 Gen 1 ports
2 x USB 2.0 headers support additional 4 USB 2.0 ports
Audio
Realtek 7.1 Surround Sound High Denition Audio CODEC*
- Supports: Jack detection, Front Panel Jack-retasking
- Supports up to 24-Bit/192kHz playback
* A chassis with an HD audio module in the front panel is required to support 7.1
Surround Sound audio output.
Back Panel I/O Ports
2 x USB 3.2 Gen 1 ports (2 x Type-A)
2 x USB 2.0 ports (2 x Type-A)
2 x DisplayPort
1 x HDMI®port
1 x D-Sub port
1 x Intel®1Gb Ethernet
3 x Audio jacks
1 x PS/2 keyboard (purple) port
1 x PS/2 mouse (green) port
Internal I/O
Connectors
Fan and cooling related
1 x 4-pin CPU Fan header
2 x 4-pin Chassis Fan headers
Power related
1 x 24-pin Main Power connector
1 x 8-pin +12V Power connector
Storage related
2 x M.2 slots (Key M)
4 x SATA 6Gb/s ports
(continued on the next page)

viii
Pro B660M-C D4 specications summary
Internal I/O
Connectors
USB
1 x USB 3.2 Gen 1 connector (supports USB Type-C®)
1 x USB 3.2 Gen 1 header supports additional 2 USB 3.2 Gen 1 ports
2 x USB 2.0 headers support additional 4 USB 2.0 ports
Miscellaneous
1 x Clear CMOS header
1 x Chassis Intrusion header
2 x COM Port headers
1 x Front Panel Audio header (AAFP)
1 x COM debug header
1 x LPT header
1 x Mono-out header(with Amp IC)
1 x M.2 slot (Key E)
1 x SMBUS header
1 x Speaker header
1 x 10-1 pin System Panel header
Special Features
ASUS EZ DIY
- Box Headers
Bespoke Motherboard Design & Business Focused Features
- Q-LED Core
- ASUS Self Recovering BIOS
- ASUS Event Log
- ASUS Commercial BIOS kit
- Anti-Moisture
- 24/7 Reliability
- Overcurrent Protection
TPM IC onboard
Software Features
ASUS Exclusive Software
IT Management software supported
- ASUS Control Center Express(ACCE)
BIOS 128Mb Flash ROM
Manageability WOL by PME, PXE
Operating System Windows®11 - 64 bit
Windows®10 - 64 bit
Form Factor mATX Form Factor
9.6 inch x 9.6 inch (24.4 cm x 24.4 cm)
Specications are subject to change without notice. Refer to the ASUS website for the
latest specications.

1-1
1
Pro B660M-C D4
Product Introduction
1.1 Before you proceed
Take note of the following precautions before you install motherboard components or change
any motherboard settings.
• Unplug the power cord from the wall socket before touching any component.
• Before handling components, use a grounded wrist strap or touch a safely grounded
object or a metal object, such as the power supply case, to avoid damaging them due
to static electricity.
• Before you install or remove any component, ensure that the ATX power supply is
switched off or the power cord is detached from the power supply. Failure to do so
may cause severe damage to the motherboard, peripherals, or components.
Unplug the power cord before installing or removing the motherboard. Failure to do so can
cause you physical injury and damage motherboard components.
1.2 Motherboard overview
Place this
side towards
the rear of the
chassis
SATA6G_12SATA6G_34
VGA
PCIEX1(G3)_1
PCIEX1(G3)_2
SPEAKER
CHASSIS
CLRTC F_PANEL
COM_DEBUG
USB_1011USB_78
LPT
U32G1_34U32_9
AAFP
MONO_OUT
SMBUS
ATX_12V
ATX_PWR
CPU_FAN
CHA_FAN1
CHA_FAN2
BATTERY
PCIEX16(G4)
Super
I/O
DIGI+
VRM
24.4cm(9.6in)
24.4cm(9.6in)
Intel®
B660
DDR4 DIMM_B1 (64bit, 288-pin module)
2280
2260
2280 2260 2242
2230
2242
M.2_2(SOCKET3)
M.2_2(SOCKET3)
PCIE SATA Optane Memory
4.0 X4 X V
M.2_1(SOCKET3)
DDR4 DIMM_B2 (64bit,288-pin module) DDR4 DIMM_A1 (64bit, 288-pin module) DDR4 DIMM_A2 (64bit, 288-pin module)
AUDIO
KBMS
HDMI_DP1
DP2
LAN_USB_56
U32G1_12
128Mb
BIOS
TPM
COM1COM2
Ethernet
Audio
Codec
M.2_1(SOCKET3)
PCIE SATA
4.0 X4 X
M.2(WIFI)
LGA1700
65 1 24
2111 20121016 41315 14
5
8
9
17
6
7
3
4
19
18
The pin denitions in this chapter are for reference only. The pin names depend on the
location of the header/jumper/connector.

1-2
1.2.1 Layout contents
1. CPU socket
The motherboard comes with a surface mount Intel®Socket LGA1700 designed for 12th Gen
Intel®Core™, Pentium®Gold and Celeron®Processors.
For more details, refer to Central Processing Unit (CPU).
2. DDR4 DIMM slots
The motherboard comes with Dual Inline Memory Modules (DIMM) slots designed for DDR4
(Double Data Rate 4) memory modules.
For more details, refer to System memory.
3. Expansion slots
This motherboard supports one PCIe 4.0 x16 graphics card and two PCIe 3.0 x1 network
cards, SCSI cards or other cards that comply with the PCI Express specication.
4. Fan headers
The Fan headers allow you to connect fans to cool the system.
5. Power connectors
These Power connectors allow you to connect your motherboard to a power supply. The
power supply plugs are designed to t in only one orientation. Find the proper orientation and
push down rmly until the power supply plugs are fully inserted.
Ensure to connect the 8-pin power plug.
• We recommend that you use a PSU with a higher power output when conguring a
system with more power-consuming devices. The system may become unstable or
may not boot up if the power is inadequate.
• If you are uncertain about the minimum power supply requirement for your system, we
recommend you to refer to online resources for Power Supply Wattage Calculator.
6. M.2 slots (Key M)
The M.2 slots allow you to install M.2 devices such as M.2 SSD modules.
• Intel®12th Gen Processors
M.2_1 slot (Key M), type 2242/2260/2280
- Intel®12th processors support PCIe 4.0 x4 mode
• Intel®B660 Chipset
M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode)
GND FAN PWR FAN IN FAN PWM
FAN PWM
FAN IN
FAN PWR
GND
FAN PWM
FAN IN
FAN PWR
GND
Chapter 1: Product Introduction

1-3
7. SATA 6Gb/s ports
The SATA 6Gb/s ports allow you to connect SATA devices such as optical disc drives and
hard disk drives via SATA cables.
8. USB 3.2 Gen 1 connector (supports USB Type-C®)
The USB 3.2 Gen 1 connector (USB Type-C®) allows you to connect a
USB 3.2 Gen 1 module for an additional USB 3.2 Gen 1 Type-C®port.
The connector provides a data transfer speed of up to 5 Gb/s.
The USB 3.2 Gen 1 module is purchased separately.
9. USB 3.2 Gen 1 header
The USB 3.2 Gen 1 header allows you to connect a USB 3.2 Gen
1 module for additional USB 3.2 Gen 1 ports. The USB 3.2 Gen 1
header provides data transfer speeds of up to 5 Gb/s.
The USB 3.2 Gen 1 module is purchased separately.
10. USB 2.0 headers
The USB 2.0 headers allow you to connect a USB module for additional USB
2.0 ports. The USB 2.0 headers provide data transfer speeds of up to 480 Mb/s.
DO NOT connect a 1394 cable to the USB connectors. Doing so will
damage the motherboard!
The USB 2.0 module is purchased separately.
11. Chassis intrusion header
This header is for a chassis-mounted intrusion detection sensor or switch.
Connect one end of the chassis intrusion sensor or switch cable to this
header. The chassis intrusion sensor or switch sends a high-level signal to this
header when a chassis component is removed or replaced. The signal is then
generated as a chassis intrusion event.
12. Clear CMOS header
This header allows you to clear the CMOS RTC RAM data of the system setup
information such as date, time, and system passwords.
To erase the RTC RAM:
1. Turn OFF the computer and unplug the power cord.
2. Use a metal object such as a screwdriver to short the two pins.
3. Plug the power cord and turn ON the computer.
4. Hold down the <Del> key during the boot process and enter BIOS Setup to re-
enter data.
If the steps above do not help, remove the onboard battery and short the two pins again to
clear the CMOS RTC RAM data. After clearing the CMOS, reinstall the battery.
SBU2
SBU1
CC1
VBUS
RX1-
RX1+
GND
TX1-
TX1+
VBUS
VBUS
TX2+
TX2-
GND
RX2+
RX2-
GND
D-
D+
CC2
USB3+5V
IntA_P3_SSRX-
IntA_P3_SSRX+
GND
IntA_P3_SSTX-
IntA_P3_SSTX+
GND
IntA_P3_D-
IntA_P3_D+
GND
PIN 1
USB3+5V
IntA_P4_SSRX-
IntA_P4_SSRX+
GND
IntA_P4_SSTX-
IntA_P4_SSTX+
GND
IntA_P4_D-
IntA_P4_D+
USB+5V USB_P7- USB_P7+ GND NC
USB+5V
USB_P8-
USB_P8+
GND
PIN 1
+5VSB_MB Chassis Signal GND
CHASSIS
CLRTC
+3V_BAT GND
PIN 1
Pro B660M-C D4

1-4
13. COM Port headers
These headers are for serial (COM) ports. Connect the serial port module cables
to these headers, then install the modules to slot openings at the back of the
system chassis.
14. COM Debug header
This header allows connection to a COM Debug card.
The COM Debug Card is purchased separately.
15. Front panel audio header
This header is for a chassis-mounted front panel audio I/O module that
supports HD audio standard. Connect one end of the front panel audio I/O
module cable to this header.
• We recommend that you connect a high-denition front panel
audio module to this header to avail of the motherboard’s high-
denition audio capability.
• If you want to connect a high-denition front panel audio module
to this header, set the Front Panel Type item in the BIOS Setup
to [HD Audio]. By default, this header is set to [HD Audio].
16. LPT header
The LPT (Line Printing Terminal) header supports devices such as
a printer. LPT standardizes as IEEE 1284, which is the parallel port
interface on IBM PC-compatible computers.
17. M.2 slot (Key E)
This slot allows you to install an M.2 (WIFI) module.
The M.2 Wi-Fi module is purchased separately.
18. Mono-out header
This internal Mono-out header allows connection to an internal, low power
speaker for basic system sound capability. The subsystem is capable of driving
a speaker load of 3 Watts RMS at 4 Ohms.
19. System Management Bus header
The System Management Bus (SMBus) connector allows you to
connect a SMBus device. This connector is generally used for
communication with the system and power management-related
tasks.
COM
PIN 1
DCD
TXD
GND
RTS
RI
RXD
DTR
DSR
CTS
PIN 1
GND GND O_COM1_TXD1
SOUTC_P80
+3V
COM_DEBUG
AAFP
AGND NC SENSE1_RETUR SENSE2_RETUR
PORT1 L
PORT1 R PORT2 R
SENSE_SEND
PORT2 L
HD-audio-compliant
pin definition
PIN 1
O_LPT_XSTB#_R
O_LPT_XPD0_R O_LPT_XPD1_R O_LPT_XPD2_R O_LPT_XPD3_R O_LPT_XPD4_R O_LPT_XPD5_R O_LPT_XPD6_R O_LPT_XPD7_R O_LPT_ACK#_R
O_LPT_BUSY_R
O_LPT_PE_R
O_LPT_SLCT_R
O_LPT_XAFD#_R O_LPT_ERROR#_R O_LPT_XINIT#_R O_LPT_XSLIN#_R GND GND GND GND GND GND GND GND
SMBUS
SMBUS_CLK
GND
SMBUS_DATA
PIN 1
R_OUT-
R_OUT+
PIN 1
MONO-OUT
Chapter 1: Product Introduction

1-5
20. Speaker header
The 4-pin header is for the chassis-mounted system warning speaker. The
speaker allows you to hear system beeps and warnings.
21. 10-1 pin System Panel header
This header supports several chassis-mounted functions.
• System power LED (2-pin +PWR_LED-)
This 2-pin header is for the system power LED. Connect the chassis
power LED cable to this header. The system power LED lights up
when you turn on the system power, and blinks when the system is in
sleep mode.
• Hard disk drive activity LED (2-pin +HDD_LED-)
This 2-pin header is for the HDD Activity LED. Connect the HDD
Activity LED cable to this header. The HDD LED lights up or flashes
when data is read from or written to the HDD.
• Power button/Soft-off button (2-pin PWR_BTN)
This header is for the system power button.
• Reset button (2-pin RESET)
This 2-pin header is for the chassis-mounted reset button for system reboot without
turning off the system power.
+5V GND GND Speaker Out
SPEAKER
PIN 1
PIN 1
PWR_BTN
PWR_LED+ PWR_LED- PWR GND
HDD_LED+
HDD_LED-
Ground
HWRST#
(NC)
F_PANEL
+PWR_LED-
+HDD_LED- RESET
Pro B660M-C D4

1-6
1.2.2 Rear panel connectors
1 2
8 10 11
43 5 6 7
9 2
ACT/LINK
LED
SPEED
LED
Ethernet port
1. PS/2 Mouse (green) port. This port is for a PS/2 mouse.
2. DisplayPorts. These ports are for DisplayPort-compatible devices.
3. Video Graphics Adapter (VGA) port. This 15-pin port is for a VGA monitor or other
VGA-compatible devices.
4. USB 3.2 Gen 1 (up to 5Gbps) ports. These Universal Serial Bus (USB) ports connect
to USB 3.2 Gen 1 devices.
5. Ethernet port. This port allows Gigabit connection to a Local Area Network (LAN)
through a network hub. Refer to the table below for the Ethernet port LED indications.
Ethernet port LED indications
6. Line In port (light blue). This port connects the tape, CD, DVD player, or other audio
sources.
7. Line Out port (lime). This port connects a headphone or a speaker. In 4-channel,
5.1-channel, and 7.1-channel congurations, the function of this port becomes Front
Speaker Out.
8. PS/2 keyboard (purple) port. This port is for a PS/2 keyboard.
Speed LED
Status Description
OFF 10Mbps connection
ORANGE 100Mbps connection
GREEN 1Gbps connection
Activity Link LED
Status Description
OFF No link
ORANGE Linked
BLINKING Data activity
Chapter 1: Product Introduction

1-7
9. HDMI®port. This port is for a High-Denition Multimedia Interface (HDMI®) connector,
and is HDCP compliant allowing playback of HD DVD, Blu-ray, and other protected
content.
10. USB 2.0 ports. These Universal Serial Bus (USB) ports are for USB 2.0 devices.
11. Microphone port (pink). This port connects a microphone.
Refer to the audio conguration table for the function of the audio ports in 2, 4, 5.1, or
7.1-channel conguration.
Audio 2, 4, 5.1 or 7.1-channel conguration
Port Headset
2-channel 4-channel 5.1-channel 7.1-channel
Light Blue
(Rear panel) Line In Rear Speaker Out Rear Speaker Out Rear Speaker Out
Lime (Rear panel) Line Out Front Speaker Out Front Speaker Out Front Speaker Out
Pink (Rear panel) Mic In Mic In Bass/Center Bass/Center
Lime (Front panel) — — — Side Speaker Out
Pink (Front panel) — — — Mic In
A chassis with an HD audio module in the front panel is required to support 7.1-channel
audio output.
Pro B660M-C D4

1-8
1.3 Central Processing Unit (CPU)
This motherboard comes with a surface mount Intel®Socket LGA1700 for
12th Gen Intel®Core™, Pentium®Gold and Celeron®Processors.
Unplug all power cables before installing the CPU.
• Ensure that you install the correct CPU designed for LGA1700 socket only. DO NOT
install a CPU designed for LGA1155, LGA1156, LGA1151, and LGA1200 sockets on
the LGA1700 socket.
• ASUS will not cover damages resulting from incorrect CPU installation/removal,
incorrect CPU orientation/placement, or other damages resulting from negligence by
the user.
Installing the CPU
Take caution when lifting the load
lever, ensure to hold onto the load
lever when releasing the load
lever. Letting go of the load lever
immediately after releasing it may
cause the load lever to spring
back and cause damage to your
motherboard.
Chapter 1: Product Introduction

1-9
Pro B660M-C D4

1-10
1.4 System memory
This motherboard comes with four Double Data Rate 4 (DDR4) Dual Inline Memory Module
(DIMM) sockets. The gure illustrates the location of the DDR4 DIMM sockets:
DIMM_B2
DIMM_B1
DIMM_A2
DIMM_A1
Channel Sockets
Channel A DIMM_A1 & DIMM_A2
Channel B DIMM_B1 & DIMM_B2
• You may install varying memory sizes in Channel A and Channel B. The system
maps the total size of the lower-sized channel for the dual-channel conguration. Any
excess memory from the higher-sized channel is then mapped for single-channel
operation.
• A DDR4 memory module is notched differently from a DDR, DDR2, or DDR3 module.
DO NOT install a DDR, DDR2, or DDR3 memory module to the DDR4 slot.
• Intel® 12th Gen processors support 3200/3000/2933/2800/2666/2400/2133 natively.
• The default memory operation frequency is dependent on its Serial Presence Detect
(SPD), which is the standard way of accessing information from a memory module.
Under the default state, some memory modules for overclocking may operate at a
lower frequency than the vendor-marked value.
• For system stability, use a more efcient memory cooling system to support a full
memory load.
• Always install DIMMs with the same CAS latency. For optimal compatibility, we
recommend that you install memory modules of the same version or date code (D/C)
from the same vendor. Check with the retailer to get the correct memory modules.
• Refer to www.asus.com for the Memory QVL (Qualied Vendors Lists), and memory
data rate depends on the CPU types.
Recommended memory congurations
DIMM_A1
DIMM_A2
DIMM_A2
DIMM_B2
DIMM_A2
DIMM_B1
DIMM_B2
Chapter 1: Product Introduction

1-11
To remove a DIMM
B
A
Installing a DIMM
1 2
B
A
A
Pro B660M-C D4

1-12 Chapter 1: Product Introduction