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ASUS · AM4 · B450M

ASUS Prime B450M-A II

Micro-ATX · DDR4 · 4 DIMMs · 5-phase VRM

Quality
40
VRM
13
Value
57
Amazon
$135
ASUS Prime B450M-A II
View ASUS Prime B450M-A II Gallery in high resolution
$135
Available Updated 2 days, 5 hours ago
Overall40.4
VRM13.0
Chipset67.0
Expansion / storage49.0
Connectivity33.0
Audio40.0
Quality / price56.9
$135 on Amazon Motherboard table Compare this motherboard

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Written analysis

ASUS Prime B450M-A II at a glance

The ASUS Prime B450M-A II uses the Micro-ATX form factor, AM4 socket, and B450M chipset. This is a balanced mainstream platform: enough expansion and connectivity for a performance PC without paying only for flagship extras.

Memory support is DDR4 across 4 DIMM slots, with up to 128 GB and rated overclocked speeds up to 4400 MT/s. The board can operate memory in ECC mode.

Best fit: a mainstream gaming, home, or office system with moderate expansion needs.

Power delivery

The calculated VRM score is 13.0, placing the power delivery in the basic class. The board lists 5 CPU power phases, 50 A power stages in a 5+1 layout. CPU power input is listed as 1. Keep it paired with lower-power processors and avoid sustained overclocked loads.

Expansion and storage

The expansion and storage score is 49.0: focused on the essentials. The platform supports PCIe 3.0. Physical expansion includes 3 ×16 slots, and 2 ×1.

On-board storage consists of 1 M.2 slot supporting PCIe 3.0 x4 and 6 SATA ports. Supported M.2 lengths are listed as 2242, 2260, 2280, 22110. The single M.2 slot makes drive planning more important if future expansion matters.

Connectivity and rear I/O

The connectivity score is 33.0, rated essential. There is no recorded onboard Wi-Fi ; wired networking is Realtek® RTL8111H at up to 1000 Mbps. The recorded USB provision is 6 rear connections and 6 front-panel connections. The specification sheet below separates every USB speed and connector type.

Display connectivity includes HDMI. These motherboard outputs require a processor with integrated graphics.

Audio

The audio score is 40.0. This is a standard onboard solution using Realtek ALC887/897. It covers normal gaming and communication; demanding headphones or production work still benefit from an external interface. The rear panel has 3 analogue jacks.

Buying verdict

Overall quality is 40.40, a basic but usable result for office, media, and budget gaming systems.

At the recorded Amazon price, the quality-to-price score is 56.9—a balanced value for its feature class.

Board data

Full specifications

Platform, expansion, storage, rear I/O, internal headers, networking, audio, and board controls in one sheet.

General

Manufacturer
ASUS
Motherboard
ASUS Prime B450M-A II
Chipset / socket
B450M / AM4
Form factor
Micro-ATX
Launch price
—
Amazon price
$135
Availability
In stock
Price updated
2 days, 5 hours ago

VRM

CPU phases
5 (50 A)
Power design
5+1
EPS connector
1

Memory

Type / slots
DDR4 / 4 DIMMs
Max capacity / OC
128 GB / 4400 MT/s
Per DIMM
32 GB
XMP / EXPO
Not recorded
ECC
Operates in ECC mode

PCIe

Supported version
PCIe 3.0
x16 physical
3
x16 Gen 3
3
x1 physical
2

Storage

M.2 slots
1
M.2 lengths
2242, 2260, 2280, 22110
M.2 modes
PCIe 3.0 x4
SATA ports
6

Display outputs

HDMI
Yes
DisplayPort
No
USB-C DisplayPort
No

USB

Rear USB 3.2 Gen 1 Type-A 5 Gbps
4
Rear USB 3.2 Gen 2 Type-A 10 Gbps
2
Front USB 2.0
4
Front USB 3.2 Gen 1 Type-A 5 Gbps
2
Header USB 2.0
4
Header USB 3.2 Gen 1 Type-A 5 Gbps
2

Networking

Ethernet
Realtek® RTL8111H
LAN ports
1
LAN speed
1000 Mbps
Wi-Fi
Not included
Bluetooth
No

Audio

Chipset
Realtek ALC887/897
Analog jacks
3
Gold-plated jacks
No
Optical S/PDIF
No
Spatial audio
No

Buttons

BIOS flashback
Yes
Clear CMOS
No
Q-Flash Plus
No
Smart button
No
Onboard start / reset
No

Additional information

Memory notes
Supports DDR4 Un-buffered Memory with speeds from 2133 MHz up to 4400 MHz (O.C.). ECC Memory (ECC mode) support varies by CPU. The maximum memory frequency supported also varies by processor. Compatible with 3rd/2nd/1st Gen AMD Ryzen, 2nd/1st Gen AMD Ryzen with Radeon Vega Graphics, and Athlon with Radeon Vega Graphics processors.
Display notes
Video output requires a CPU with integrated graphics, such as 2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics or Athlon™ with Radeon™ Vega Graphics Processors. Graphics specifications may vary between CPU types.
Expansion notes
The motherboard has three physical PCIe 3.0 x16 slots. One operates at x16 mode, one at x8 mode, and one at x4 mode. There are also two PCIe 2.0 x1 slots. Slot configuration and performance depend on the installed CPU (Ryzen or Athlon) and the AMD B450 chipset.
M.2_1
3.0 4 · SATA · 2242, 2260, 2280, 22110 · CPU
RAID
SATA (['0', '1', '10'])
Storage notes
The text is ambiguous regarding M.2 slot functionality. It lists two separate descriptions for what appears to be a single M.2 slot. One description states 'SATA mode' support, while the other states 'SATA & PCIE 3.0 x 4 mode'. This may be dependent on the installed CPU. The 6 SATA ports are provided by two sources: 4 from the AMD B450 chipset and 2 from another source (likely CPU).
USB notes
Primary USB data lists totals of 6 rear and 6 front ports. Rear ports consist of 2x USB 3.2 Gen 2 (Type-A) and 4x USB 3.2 Gen 1 (Type-A). Front ports are provided via internal headers: 4x USB 2.0 (from 2 headers) and 2x USB 3.2 Gen 1 (from one 19-pin header).
Audio notes
Premium audio capacitors. Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback. Features LED-illuminated design, Audio Shielding, and Dedicated audio PCB layers. A chassis with an HD audio module in the front panel is required to support 8-channel audio output.
Button notes
The motherboard includes one Clear CMOS jumper.
Fan / RGB headers
1 CPU · — OPT · — AIO · 2 chassis · — ARGB · 1 RGB
Other headers
Front audio · System panel · TPM
Dimensions
24.4 cm x 24 cm

Extracted notes sit here. Official manufacturer copy is at the bottom of the page.

Amazon

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Vendor copy

Official manufacturer data

Raw manufacturer text kept for reference. Structured specs above are extracted from this copy and are the source for scores and tables.

Memory

4 x DIMM, Max. 128GB, DDR4 4400(O.C)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3400(O.C.)/3300(O.C.)/3200(O.C.)/3000(O.C.)/2800(O.C.)/2666/2400/2133 MHz Un-buffered Memory *,3rd/2nd/1st Gen AMD Ryzen™/ 2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics/ Athlon™ with Radeon™ Vega Graphics Processors,Dual Channel Memory Architecture,ECC Memory (ECC mode) support varies by CPU.,* The maximum memory frequency supported varies by processor.

Graphics

1 x HDMI™ port,Integrated Graphics in the 2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics/ Athlon™ with Radeon™ Vega Graphics Processors *,*Graphics specifications may vary between CPU types.

Expansion slots

3rd/2nd/1st Gen AMD Ryzen™ Processors,1 x PCIe 3.0 x16 (x4 mode),AMD B450 chipset,1 x PCIe 3.0 x16 (x16 mode),1 x PCIe 3.0 x16 (x8 mode),AMD Athlon™ with Radeon™ Vega Graphics Processors,2 x PCIe 2.0 x1

Storage

Total supports 1 x M.2 slot(s) and 6 x SATA 6Gb/s ports,3rd/2nd/1st Gen AMD Ryzen™/ 2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics : *1,Athlon™ with Radeon™ Vega Graphics Processors : *1,3rd/2nd/1st Gen AMD Ryzen™/ 2nd and 1st Gen AMD Ryzen™ with Radeon™ Vega Graphics/ Athlon™ with Radeon™ Vega Graphics Processors : ,1 x M.2 Socket 3, with M key, type 2242/2260/2280/22110 storage devices support (SATA mode),1 x M.2 Socket 3, with M key, type 2242/2260/2280/22110 storage devices support (SATA & PCIE 3.0 x 4 mode),2 x SATA 6Gb/s port(s),,AMD B450 chipset : ,Support Raid 0, 1, 10,4 x SATA 6Gb/s port(s),

USB

2 x USB 3.2 Gen 2 (up to 10Gbps) port(s)(2 x Type-A),Front USB Port ( Total 6 ),Rear USB Port ( Total 6 ),4 x USB 3.2 Gen 1 port(s)(4 x Type-A),2 x USB 3.2 Gen 1 port(s),4 x USB 2.0 port(s)

Internal I/O

1 x COM port header,1 x USB 3.2 Gen 1(up to 5Gbps) connector(s) support(s) additional 2 USB 3.2 Gen 1 port(s) (19-pin),2 x Chassis Fan connector(s) (2 x 4-pin),1 x M.2 Socket 3 with M key, type 2242/2260/2280/22110 storage devices support (SATA & PCIE 3.0 x 4 mode),1 x RGB Header,1 x CPU Fan connector(s) (1 x 4-pin),2 x USB 2.0 connector(s) support(s) additional 4 USB 2.0 port(s),1 x SPI TPM header,1 x COM port(s) connector(s),6 x SATA 6Gb/s connector(s),1 x S/PDIF out header(s),1 x 24-pin EATX Power connector(s),1 x 8-pin ATX 12V Power connector(s),1 x Front panel audio connector(s) (AAFP),1 x System panel(s),1 x Clear CMOS jumper(s),1 x COM port header,1 x Speaker connector

Rear I/O

2 x USB 3.2 Gen 2 (teal blue) (2 x Type-A),1 x BIOS FlashBack™ Button(s),4 x USB 3.2 Gen 1 (blue) Type-A,1 x PS/2 keyboard/mouse combo port(s),1 x DVI-D,1 x D-Sub,1 x HDMI,1 x LAN (RJ45) port(s),3 x Audio jack(s)

Audio

Premium audio capacitors,Realtek ALC887/8977.1-Channel High Definition Audio CODEC *,- Supports : Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback,- LED-illuminated design,- Audio Shielding,- Dedicated audio PCB layers,Audio Feature :,* Choose the chassis with HD audio module in front panel to support 8-channel audio output.

Special features

ASUS 5X PROTECTION III
- ASUS DIGI+ VRM
- ASUS LANGuard
- ASUS Overvoltage Protection
- ASUS SafeSlot Core
- ASUS Stainless-Steel Back I/O
ASUS Q-Design
- ASUS Q-DIMM
- ASUS Q-Slot
ASUS Thermal Solution
- Aluminum heatsink design
ASUS EZ DIY
- BIOS FlashBack™ button
- BIOS FlashBack™ LED
AURA Sync
- AURA RGB header
ASUS Lighting Control

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