Asus PRIME B450M-K II Manual

About this guide

This user guide contains the information you need when installing and configuring 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, upgrade BIOS using the EZ Flash Utility and support on RAID.

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.

Information to prevent damage to the components and injuries to yourself when trying to complete a task.

Instructions that you MUST follow to complete a task.

NOTE: Tips and additional information to help you complete a task.

Package contents

Check your motherboard package for the following items.

If any of the above items is damaged or missing, contact your retailer.

PRIME B450M-K II specifications summary

Specifications are subject to change without notice. Refer to the ASUS website for the latest specifications.

Product Introduction

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.

Motherboard overview

Unplug the power cord before installing or removing the motherboard. Failure to do so can cause you physical injury and damage motherboard components.

Layout contents

1. CPU socket
   The motherboard comes with an AMD Socket AM4 designed for 3^rd/2^nd/1^st Gen AMD Ryzen™ / 2^nd and 1^st Gen AMD Ryzen™ with Radeon™ Vega Graphics / Athlon™ with Radeon™ Vega Graphics 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 3.0 x16 graphics card and two PCIe 2.0 x1 network cards, SCSI cards and other cards that comply with the PCI Express specification.
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 fit in only one orientation. Find the proper orientation and push down firmly until the power supply plugs are fully inserted.

Ensure to connect the 8-pin power plug.

• For a fully configured system, we recommend that you use a power supply unit (PSU) that complies with ATX 12V Specification 2.0 (or later version) and provides a minimum power of 350W.
• We recommend that you use a PSU with a higher power output when configuring 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 Slot (Key M)

The M.2 slot allows you to install an M.2 device such as an M.2 SSD module.

• For 3^rd/2^nd/1^st Gen AMD Ryzen™ / 2^nd and 1^st Gen AMD Ryzen™ with Radeon™ Vega Graphics Processors, M.2 slot (Key M), type 2242/2260/2280 (supports PCIe 3.0 x4 & SATA modes).
• For Athlon™ with Radeon™ Vega Graphics Processors, M.2 slot (Key M), type 2242/2260/2280 (supports SATA mode).

7. SATA 6Gb/s portsThe SATA 6Gb/s ports allow you to connect SATA devices such as optical disc drives and hard disk drives via a SATA cable.
8. 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.

9. USB 2.0 headers
   
   The USB 2.0 headers allow you to connect USB modules 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.

10. Clear CMOS header
    
    This header allows you to clear the CMOS RTC RAM data of the system setup CLRTC 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. H old down the <Del> key during the boot process and enter BIOS setup to reenter 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.

11. COM Port header
    
    This header is for a serial (COM) port. Connect the serial port module cable to this header, then install the module to a slot opening at the back of the system chassis.
12. Front Panel Audio header AAFP
    
    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-definition front panel audio module to this header to avail of the motherboard's high-definition audio capability.
• If you want to connect a high-definition front panel audio module to this header, set the Front Panel Type item in the BIOS setup to [HD HD-audio-compliant Audio]. By default, this header is set to [HD Audio].

13. S/PDIF Out header
    
    This header is for an additional Sony/Philips Digital Interface (S/PDIF) port. Connect the S/PDIF Out module cable to this header, then install the module to a slot opening at the back of the system chassis.
14. Speaker header
    
    The 4-pin header is for the chassis-mounted system warning speaker. The speaker allows you to hear system beeps and warnings.
15. SPI TPM header
    
    This header supports a Trusted Platform Module (TPM) system with a Serial Peripheral Interface (SPI), allowing you to securely store keys, digital certificates, passwords, and data. A TPM system also helps enhance network security, protects digital identities, and ensures platform integrity.
16. 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 PIN 1 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.

17. BIOS FlashBack™ LED
    The FlashBack™ LED lights up or blinks to indicate the status of the BIOS FlashBack™.

Scan the QR code for more information on BIOS FlashBack function.

Rear panel connectors

1. Video Graphics Adapter (VGA) port. This 15-pin port is for a VGA monitor or other VGA-compatible devices.
2. PS/2 Keyboard/Mouse combo port. This port is for a PS/2 keyboard or mouse.
3. USB 2.0 ports. These 4-pin Universal Serial Bus (USB) ports are for USB 2.0 devices.
4. 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

5. Line In port (light blue). This port connects the tape, CD, DVD player, or other audio sources.
6. Line Out port (lime). This port connects a headphone or a speaker. In 4-channel, 5.1-channel, and 7.1-channel configurations, the function of this port becomes Front Speaker Out.
7. BIOS FlashBack^TM button. Press the BIOS FlashBack^TM button for three seconds until the FlashBack^TM LED blinks three times, indicating that the BIOS FlashBack^TM function is enabled.
8. DVI-D port. This port is for any DVI-D compatible device.

DVI-D can not be converted to output from RGB Signal to CRT and is not compatible with DVI-I.

9. HDMI^TM port. This port is for a High-Definition Multimedia Interface (HDMI^TM) connector, and is HDCP compliant allowing playback of HD DVD, Blu-ray, and other protected content.
10. USB 3.2 Gen 1 (up to 5Gbps) ports. These 9-pin Universal Serial Bus (USB) ports connect to USB 3.2 Gen 1 devices.
11. USB 3.2 Gen 1 (up to 5Gbps) port with BIOS FlashBack^TM function. Insert a USB storage device to this USB 3.2 Gen 1 port to run BIOS FlashBack^TM.
12. Microphone port (pink). This port connects a microphone.

Refer to the audio configuration table for the function of the audio ports in 2, 4, 5.1, or 7.1-channel configuration.

Audio 2, 4, 5.1 or 7.1-channel configuration

To configure a 7.1-channel audio output:
Use a chassis with HD audio module in the front panel to support a 7.1-channel audio output.

Central Processing Unit (CPU)

The motherboard comes with an AMD Socket AM4 designed for 3^rd/2^nd/1^st Gen AMD Ryzen™ / 2^nd and 1^st Gen AMD Ryzen™ with Radeon™ Vega Graphics / Athlon™ with Radeon™ Vega Graphics Processors.

Unplug all power cables before installing the CPU.

The AM4 socket has a different pinout design. Ensure that you use a CPU designed for the AM4 socket. The CPU fits in only one correct orientation. DO NOT force the CPU into the socket to prevent bending the connectors on the socket and damaging the CPU!

Installing the CPU

Apply the Thermal Interface Material to the CPU heatsink and CPU before you install the heatsink and fan if necessary.

System memory

This motherboard comes with two Double Data Rate 4 (DDR4) Dual Inline Memory Module (DIMM) sockets. The figure illustrates the location of the DDR4 DIMM sockets:

• 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 configuration. Any excess memory from the higher-sized channel is then mapped for single-channel operation.
• 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.
• 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.

• 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 efficient memory cooling system to support a full memory load (2 DIMMs).
• Refer to www.asus.com for the latest Memory QVL (Qualified Vendors Lists).

Recommended memory configuration

Installing a DIMM

To remove a DIMM

BIOS and RAID Support

Knowing BIOS

The new ASUS UEFI BIOS is a Unified Extensible Interface that complies with UEFI architecture, offering a user-friendly interface that goes beyond the traditional keyboardonly BIOS controls to enable a more flexible and convenient mouse input. You can easily navigate the new UEFI BIOS with the same smoothness as your operating system. The term "BIOS" in this user manual refers to "UEFI BIOS" unless otherwise specified.

BIOS (Basic Input and Output System) stores system hardware settings such as storage device configuration, overclocking settings, advanced power management, and boot device configuration that are needed for system startup in the motherboard CMOS. In normal circumstances, the default BIOS settings apply to most conditions to ensure optimal performance. DO NOT change the default BIOS settings except in the following circumstances:

• An error message appears on the screen during the system bootup and requests you to run the BIOS Setup.
• You have installed a new system component that requires further BIOS settings or update.

Inappropriate BIOS settings may result to instability or boot failure. We strongly recommend that you change the BIOS settings only with the help of a trained service personnel.

• When downloading or updating the BIOS file, rename it as PB450MK2.CAP for this motherboard.
• BIOS settings and options may vary due to different BIOS release versions. Please refer to the latest BIOS version for settings and options.

BIOS Setup program

Use the BIOS Setup to update the BIOS or configure its parameters. The BIOS screens include navigation keys and brief onscreen help to guide you in using the BIOS Setup program.

Entering BIOS at startup
To enter BIOS Setup at startup, press <Delete> or <F2> during the Power-On Self Test (POST). If you do not press <Delete> or <F2>, POST continues with its routines.

Entering BIOS Setup after POST
To enter BIOS Setup after POST:

• Press <Ctrl>+<Alt>+<Delete> simultaneously.
• Press the reset button on the system chassis.
• Press the power button to turn the system off then back on. Do this option only if you failed to enter BIOS Setup using the first two options.

After doing either of the three options, press <Delete> key to enter BIOS.

• Ensure that a USB mouse is connected to your motherboard if you want to use the mouse to control the BIOS setup program.
• If the system becomes unstable after changing any BIOS setting, load the default settings to ensure system compatibility and stability. Select the Load Optimized Defaults item under the Exit menu or press hotkey <F5>.
• If the system fails to boot after changing any BIOS setting, try to clear the CMOS and reset the motherboard to the default value.
• The BIOS setup program does not support Bluetooth devices.

BIOS menu screen
The BIOS Setup program can be used under two modes: EZ Mode and Advanced Mode.

You can change modes from Setup Mode in Boot menu or by pressing the <F7> hotkey.

ASUS EZ Flash 3

The ASUS EZ Flash 3 feature allows you to update the BIOS without using an OS-based utility.

Ensure to load the BIOS default settings to ensure system compatibility and stability. Select the Load Optimized Defaults item under the Exit menu or press hotkey <F5>.

To update the BIOS by USB:

• This function can support devices such as a USB flash disk with FAT 32/16 format and single partition only.
• DO NOT shut down or reset the system while updating the BIOS to prevent system boot failure!

1. Insert the USB flash disk that contains the latest BIOS file to the USB port.
2. Enter the Advanced Mode of the BIOS setup program. Go to the Tool menu to select ASUS EZ Flash 3 Utility and press <Enter>.
3. Press <Tab> to switch to the Drive field.
4. Press the Up/Down arrow keys to find the USB flash disk that contains the latest BIOS, and then press <Enter>.
5. Press <Tab> to switch to the Folder field.
6. Press the Up/Down arrow keys to find the BIOS file, and then press <Enter> to perform the BIOS update process. Reboot the system when the update process is done.

ASUS CrashFree BIOS 3

The ASUS CrashFree BIOS 3 utility is an auto recovery tool that allows you to restore the BIOS file when it fails or gets corrupted during the updating process. You can restore a corrupted BIOS file using a USB flash drive that contains the BIOS file.

If you want to use the latest BIOS file, download the file at https://www.asus.com/support, and save it to a USB flash drive.

Recovering the BIOS
To recover the BIOS:

1. Turn on the system.
2. Insert the USB flash drive containing the BIOS file to the USB port.
3. The utility automatically checks the devices for the BIOS file. When found, the utility reads the BIOS file and enters ASUS EZ Flash 3 automatically.
4. The system requires you to enter BIOS Setup to recover the BIOS setting. To ensure system compatibility and stability, we recommend that you press <F5> to load default BIOS values.

DO NOT shut down or reset the system while updating the BIOS! Doing so can cause system boot failure!

RAID configurations

The motherboard supports RAID 0, RAID 1, and RAID 10 configuration.

For more information on configuring your RAID sets, please refer to the RAID Configuration Guide which you can find at https://www.asus.com/support, or by scanning the QR code.

RAID definitions
RAID 0 (Data striping) optimizes two identical hard disk drives to read and write data in parallel, interleaved stacks. Two hard disks perform the same work as a single drive but at a sustained data transfer rate, double that of a single disk alone, thus improving data access and storage. Use of two new identical hard disk drives is required for this setup.

RAID 1 (Data mirroring) copies and maintains an identical image of data from one drive to a second drive. If one drive fails, the disk array management software directs all applications to the surviving drive as it contains a complete copy of the data in the other drive. This RAID configuration provides data protection and increases fault tolerance to the entire system. Use two new drives or use an existing drive and a new drive for this setup. The new drive must be of the same size or larger than the existing drive.

RAID 10 is data striping and data mirroring combined without parity (redundancy data) having to be calculated and written. With the RAID 10 configuration you get all the benefits of both RAID 0 and RAID 1 configurations. Use four new hard disk drives or use an existing drive and three new drives for this setup.

ASUS contact information
ASUSTeK COMPUTER INC.
Address 1F., No. 15, Lide Rd., Beitou Dist., Taipei City 112, Taiwan
Telephone +886-2-2894-3447
Fax +886-2-2890-7798
Web site https://www.asus.com

Technical Support
Telephone +86-21-38429911
Online support https://qr.asus.com/techserv

ASUS COMPUTER INTERNATIONAL (America)
Address 48720 Kato Rd., Fremont, CA 94538, USA
Telephone +1-510-739-3777
Fax +1-510-608-4555
Web site https://www.asus.com/us/

Technical Support
Support fax +1-812-284-0883
Telephone +1-812-282-2787
Online support https://qr.asus.com/techserv

ASUS COMPUTER GmbH (Germany and Austria)
Address Harkortstrasse 21-23, 40880 Ratingen, Germany
Web site https://www.asus.com/de
Online contact https://www.asus.com/support/Product/ContactUs/Services/questionform/?lang=de-de

Technical Support
Telephone (DE) +49-2102-5789557
Telephone (AT) +43-1360-2775461
Online support https://www.asus.com/de/support