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ASUS PRIME B550M-A vs ASUS Pro B550M-C/CSM

Real specs. Clear sources.Exact models · UK & US buying links

Compared products

YOUR FIRST CHOICE

ASUS PRIME B550M-A

UK manufacturer specification · PRIME B550M-A

Full product profile Official image

Exact model & source notes

PRIME B550M-A motherboard, identified in the ASUS UK catalogue. Specifications below retain the manufacturer’s configuration and interface conditions.

Specifications checked 17 Oct 2026.

Amazon links open search results. Check the exact variant, current price and availability with the retailer.

Manufacturer specifications

WHAT DIFFERS

5 verified differences, led by Form factor and dimensions, memory type, slots and limit and storage interfaces and restrictions. Compared in full below. Not a rating.

See the 5 verified differences

THE CONTENDER

ASUS Pro B550M-C/CSM

Global manufacturer specification · Pro B550M-C/CSM

Full product profile Official image

Exact model & source notes

Pro B550M-C/CSM motherboard, identified in the ASUS Global catalogue. Specifications below retain the manufacturer’s configuration and interface conditions.

Specifications checked 17 Oct 2026.

Amazon links open search results. Check the exact variant, current price and availability with the retailer.

Manufacturer specifications

PRIME B550M-A UK & US retailers

UK & US price history: no verified listing yet

Pro B550M-C/CSM UK & US retailers

UK & US price history: no verified listing yet

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THE DIFFERENCES, MADE VISIBLE

Visual facts

Differences first. Select a topic for its graphic, sources and conditions.

How to read this comparison

Manufacturer facts for the exact models shown. Not a quality rating or a test result.
“Different” means the known values differ, not that one is better.
Missing or conflicting evidence is marked and never counts as a difference. Source chips hold each fact’s sources and conditions.

SPECIFICATIONS SIDE BY SIDE5 topics

SELECTED TOPIC

01 / 05

Form factor and dimensions

Check the exact configuration and source conditions for your use.

ASUS PRIME B550M-AmATX Form Factor 9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Manufacturer specification

Source 1

ASUS Pro B550M-C/CSMmATX Form Factor,9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Manufacturer specification

Source 1

Explore the full specifications

Plan the complete platform. Check the exact CPU-support list, required BIOS and memory validation before buying. PCIe generations and lane allocations can change with the processor. A socket match or slot count is not a guarantee that every component works together at its highest advertised setting.

WHAT CHANGES BETWEEN THEM?

Key differences

Full specifications ↓

5 verified differences, most decision-relevant first. All are also drawn in Visual facts above. Missing information stays separate.

Form factor and dimensions

In Visual facts

ASUS PRIME B550M-AmATX Form Factor 9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

ASUS Pro B550M-C/CSMmATX Form Factor,9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Sources

ASUS PRIME B550M-A

Manufacturer specification

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification

ASUS Pro B550M-C/CSM — official Global technical specifications

Check the exact configuration and source conditions for your use.

Memory type, slots and limit

In Visual facts

ASUS PRIME B550M-AAMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors 4 x DIMM, Max. 128GB, DDR4 4600(O.C)/4400(O.C)/4266(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3333(O.C.)/3200/3000/2800/2666/2400/2133 MHz Un-buffered Memory * AMD Ryzen™ 4000 G-Series Desktop Processors 4 x DIMM, Max. 128GB, DDR4 4800(O.C.)/4600(O.C)/4466(O.C.)/4400(O.C)/4266(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3333(O.C.)/3200/3000/2800/2666/2400/2133 MHz Un-buffered Memory * Dual Channel Memory Architecture ECC Memory (ECC mode) support varies by CPU. * Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).

ASUS Pro B550M-C/CSM4 x DIMM, Max. 128GB, DDR4 4866(O.C)/4800(O.C.)/4600(O.C)/4466(O.C.)/4400(O.C)/4333(O.C.)/4266(O.C.)/4200(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3400(O.C.)/3333(O.C.)/3200/3000/2933/2800/2666/2400/2133 MHz Un-buffered Memory *,* Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists), and memory frequency support depends on the CPU types.,Dual Channel Memory Architecture,ECC Memory (ECC mode) support varies by CPU.

Sources

ASUS PRIME B550M-A

Manufacturer specification

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification

ASUS Pro B550M-C/CSM — official Global technical specifications

Check the exact configuration and source conditions for your use.

Storage interfaces and restrictions

In Visual facts

ASUS PRIME B550M-ATotal supports 2 x M.2 slot(s) and 4 x SATA 6Gb/s ports AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110(PCIE 4.0 x4 and SATA modes) storage devices support AMD Ryzen™ 4000 G-Series Desktop Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110(PCIE 3.0 x4 and SATA modes) storage devices support AMD B550 Chipset: 1 x M.2_2 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support 4 x SATA 6Gb/s port(s), Support Raid 0, 1, 10

ASUS Pro B550M-C/CSMAMD Ryzen™ 5000 G-Series/ 4000 G-Series Desktop Processors:,AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors:,Total supports 2 x M.2 slot(s) and 4 x SATA 6Gb/s ports,1 x M.2_2 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support,AMD B550 Chipset:,1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280 (PCIE 4.0 x4 and SATA modes) storage devices support,1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support,4 x SATA 6Gb/s port(s),,Support Raid 0, 1, 10

Sources

ASUS PRIME B550M-A

Manufacturer specification

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification

ASUS Pro B550M-C/CSM — official Global technical specifications

Check the exact configuration and source conditions for your use.

Audio interfaces

In Visual facts

ASUS PRIME B550M-ARealtek ALC887/897 7.1 Surround Sound High Definition Audio CODEC - Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback Audio Feature: - LED-illuminated design - Audio Shielding - Dedicated audio PCB layers - Premium Japanese audio capacitors * Choose the chassis with HD audio module in front panel to support 8-channel audio output.

ASUS Pro B550M-C/CSMRealtek ALC887/8977.1 Surround Sound High Definition Audio CODEC *,- Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback,* Choose the chassis with HD audio module in front panel to support 8-channel audio output.

Sources

ASUS PRIME B550M-A

Manufacturer specification

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification

ASUS Pro B550M-C/CSM — official Global technical specifications

Check the exact configuration and source conditions for your use.

Expansion slots and restrictions

In Visual facts

ASUS PRIME B550M-AAMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors 1 x PCIe 4.0 x16 (x16 mode) AMD Ryzen™ 4000 G-Series Desktop Processors 1 x PCIe 3.0 x16 (x16 mode) AMD B550 Chipset 2 x PCIe 3.0 x1

ASUS Pro B550M-C/CSMAMD Ryzen™ 5000 G-Series/ 4000 G-Series Desktop Processors,1 x PCIe 4.0 x16 (x16 mode) *,AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors,* Support PCIe bifurcation for RAID on CPU function.,AMD B550 Chipset,1 x PCIe 3.0 x4 *1,1 x PCIe 3.0 x16 (x16 mode),1 x PCI

Sources

ASUS PRIME B550M-A

Manufacturer specification

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification

ASUS Pro B550M-C/CSM — official Global technical specifications

Check the exact configuration and source conditions for your use.

Configuration & compatibility details (1)

CPU support and BIOS requirements

ASUS PRIME B550M-AAMD AM4 Socket for AMD Ryzen™ 5000 Series/ 4000 G-Series/ 3000 Series Desktop Processors * * Refer to www.asus.com for CPU support list BIOS: 256 Mb Flash ROM, UEFI AMI BIOS

ASUS Pro B550M-C/CSMAMD AM4 Socket for AMD Ryzen™ 5000 Series/ 5000 G-Series/ 4000 G-Series/ 3000 Series Desktop Processors *,* Refer to www.asus.com for CPU support list BIOS: 256 Mb Flash ROM, UEFI AMI BIOS

Sources

ASUS PRIME B550M-A

Manufacturer specification · Exact CPU support and BIOS revision depend on the processor and the current ASUS CPU support list; the family statement is not a guarantee for every processor.

ASUS PRIME B550M-A — official UK technical specifications

ASUS Pro B550M-C/CSM

Manufacturer specification · Exact CPU support and BIOS revision depend on the processor and the current ASUS CPU support list; the family statement is not a guarantee for every processor.

ASUS Pro B550M-C/CSM — official Global technical specifications

These descriptions or measurements differ. Wording alone does not establish a different capability; check the exact configuration.

4 shared fields have the same recorded value.

WHAT EACH CHOICE ASKS OF YOU

What it brings and what to check

ASUS PRIME B550M-A

What it brings

Published motherboard interfaces and configuration are available from the exact-model ASUS specification source.
Manufacturer source

What to check

Compatibility and maximum operating modes depend on the source’s stated hardware, firmware and connection requirements; manufacturer figures are not independent measurements.
Manufacturer source

ASUS Pro B550M-C/CSM

What it brings

Published motherboard interfaces and configuration are available from the exact-model ASUS specification source.
Manufacturer source

What to check

Compatibility and maximum operating modes depend on the source’s stated hardware, firmware and connection requirements; manufacturer figures are not independent measurements.
Manufacturer source

COMPARE THE DETAILS

Full specifications

How we verify

Differences only

10 of 10 specifications Sources in each row

Source-backed specifications for ASUS PRIME B550M-A and ASUS Pro B550M-C/CSM
Specification	ASUS PRIME B550M-A	ASUS Pro B550M-C/CSM

CPU socket Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	AM4	AM4
Chipset Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	AMD B550	AMD B550
Form factor and dimensionsDifferent Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	mATX Form Factor 9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )	mATX Form Factor,9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )
CPU support and BIOS requirementsDifferent Sources ASUS PRIME B550M-A Manufacturer specification · Exact CPU support and BIOS revision depend on the processor and the current ASUS CPU support list; the family statement is not a guarantee for every processor. ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification · Exact CPU support and BIOS revision depend on the processor and the current ASUS CPU support list; the family statement is not a guarantee for every processor. ASUS Pro B550M-C/CSM — official Global technical specifications	*AMD AM4 Socket for AMD Ryzen™ 5000 Series/ 4000 G-Series/ 3000 Series Desktop Processors * Refer to www.asus.com for CPU support list BIOS: 256 Mb Flash ROM, UEFI AMI BIOS**	*AMD AM4 Socket for AMD Ryzen™ 5000 Series/ 5000 G-Series/ 4000 G-Series/ 3000 Series Desktop Processors ,* Refer to www.asus.com for CPU support list BIOS: 256 Mb Flash ROM, UEFI AMI BIOS**
Listed operating systems Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	Windows® 10 64-bit	Windows® 10 64-bit

Memory type, slots and limitDifferent Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors 4 x DIMM, Max. 128GB, DDR4 4600(O.C)/4400(O.C)/4266(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3333(O.C.)/3200/3000/2800/2666/2400/2133 MHz Un-buffered Memory * AMD Ryzen™ 4000 G-Series Desktop Processors 4 x DIMM, Max. 128GB, DDR4 4800(O.C.)/4600(O.C)/4466(O.C.)/4400(O.C)/4266(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3333(O.C.)/3200/3000/2800/2666/2400/2133 MHz Un-buffered Memory * Dual Channel Memory Architecture ECC Memory (ECC mode) support varies by CPU. * Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists).	4 x DIMM, Max. 128GB, DDR4 4866(O.C)/4800(O.C.)/4600(O.C)/4466(O.C.)/4400(O.C)/4333(O.C.)/4266(O.C.)/4200(O.C.)/4133(O.C.)/4000(O.C.)/3866(O.C.)/3733(O.C.)/3600(O.C.)/3466(O.C.)/3400(O.C.)/3333(O.C.)/3200/3000/2933/2800/2666/2400/2133 MHz Un-buffered Memory , Refer to www.asus.com for the Memory QVL (Qualified Vendors Lists), and memory frequency support depends on the CPU types.,Dual Channel Memory Architecture,ECC Memory (ECC mode) support varies by CPU.

Storage interfaces and restrictionsDifferent Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	Total supports 2 x M.2 slot(s) and 4 x SATA 6Gb/s ports AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110(PCIE 4.0 x4 and SATA modes) storage devices support AMD Ryzen™ 4000 G-Series Desktop Processors: 1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280/22110(PCIE 3.0 x4 and SATA modes) storage devices support AMD B550 Chipset: 1 x M.2_2 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support 4 x SATA 6Gb/s port(s), Support Raid 0, 1, 10	AMD Ryzen™ 5000 G-Series/ 4000 G-Series Desktop Processors:,AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors:,Total supports 2 x M.2 slot(s) and 4 x SATA 6Gb/s ports,1 x M.2_2 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support,AMD B550 Chipset:,1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280 (PCIE 4.0 x4 and SATA modes) storage devices support,1 x M.2_1 socket 3, with M Key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support,4 x SATA 6Gb/s port(s),,Support Raid 0, 1, 10

Expansion slots and restrictionsDifferent Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors 1 x PCIe 4.0 x16 (x16 mode) AMD Ryzen™ 4000 G-Series Desktop Processors 1 x PCIe 3.0 x16 (x16 mode) AMD B550 Chipset 2 x PCIe 3.0 x1	AMD Ryzen™ 5000 G-Series/ 4000 G-Series Desktop Processors,1 x PCIe 4.0 x16 (x16 mode) ,AMD Ryzen™ 5000 Series/ 3000 Series Desktop Processors, Support PCIe bifurcation for RAID on CPU function.,AMD B550 Chipset,1 x PCIe 3.0 x4 *1,1 x PCIe 3.0 x16 (x16 mode),1 x PCI

Audio interfacesDifferent Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	Realtek ALC887/897 7.1 Surround Sound High Definition Audio CODEC - Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback Audio Feature: - LED-illuminated design - Audio Shielding - Dedicated audio PCB layers - Premium Japanese audio capacitors * Choose the chassis with HD audio module in front panel to support 8-channel audio output.	Realtek ALC887/8977.1 Surround Sound High Definition Audio CODEC ,- Supports: Jack-detection, Multi-streaming, Front Panel Jack-retasking, up to 24-Bit/192kHz playback, Choose the chassis with HD audio module in front panel to support 8-channel audio output.

Network interfaces and requirements Sources ASUS PRIME B550M-A Manufacturer specification ASUS PRIME B550M-A — official UK technical specifications ASUS Pro B550M-C/CSM Manufacturer specification ASUS Pro B550M-C/CSM — official Global technical specifications	Realtek RTL8111H 1Gb Ethernet	Realtek RTL8111H 1Gb Ethernet

First product manufacturer source Second product manufacturer source

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Closest motherboards to this pair by shared key specifications. Not a popularity ranking.

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ASUS PRIME B550M-A/CSM

CPU socket: AM4
Chipset: AMD B550
Form factor and dimensions: mATX Form Factor 9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Prices & product profile

ASUS PRIME B550M-A AC

CPU socket: AM4
Chipset: AMD B550
Form factor and dimensions: mATX Form Factor 9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Prices & product profile

ASUS TUF GAMING B550M-PLUS

CPU socket: AM4
Chipset: AMD B550
Form factor and dimensions: mATX Form Factor,9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )

Prices & product profile

MSI PRO B550M-VC WIFI

Maximum memory: 128 GB
DIMM slots: 4 slots
M.2 slots: 2 slots

Prices & product profile

Each record represents an explicitly checked model and configuration. Original import: 5 Sept 2026; this is not its verification date. This is not a list of current offers or a popularity ranking.