Asus PRIME B840M-A-CSM AMD B840 AM5 Micro ATX 4 DDR5 HDMI 2 DP 2.5G LAN 3x M.2
Original price was: £163.57.£154.19Current price is: £154.19.
Asus PRIME B840M-A-CSM AMD B840 AM5 Micro ATX 4 DDR5 HDMI 2 DP 2.5G LAN 3x M.2
MPN:
90MB1J10-M0EAYC
- Form Factor: Micro ATX
- Socket: AMD AM5
- Chipset: AMD B840
- DDR Type: DDR5
Original price was: £163.57.£154.19Current price is: £154.19.
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Product Description
ASUS PRIME B840M-A-CSM Ultimate Performance Micro-ATX Motherboard
Engineered for Ryzen Performance
The ASUS PRIME B840M-A-CSM is built to support AMD Ryzenâ„¢ 9000, 8000, and 7000 Series processors using the powerful AMD B840 chipset and AM5 socket. With support for blazing-fast DDR5 RAM (up to 7600+ MT/s OC), dual PCIe 4.0 x4 M.2 slots, and high-bandwidth PCIe 4.0 graphics, this motherboard is ideal for handling heavy workloads, high-end gaming, and AI applications. Realtek 2.5Gb Ethernet provides ultra-reliable, high-speed networking, while BIOS FlashBackâ„¢ allows seamless BIOS updates without a CPU or memory installed.
Advanced Cooling and Expansion Options
Cooling is handled with precision thanks to dedicated VRM and PCH heatsinks and ASUS Fan Xpert 2+ for granular fan control. A pre-mounted I/O shield and Q-LED Core diagnostics simplify installation and troubleshooting, while SafeSlot Core+ ensures GPU slot durability. Expand your storage with three M.2 slots (PCIe 4.0 and 3.0) and four SATA ports, with full RAID support under RAIDXpert2. Rear and front USB Type-C® ports (5Gbps), plus multiple USB 10Gbps and 2.0 ports, provide comprehensive device connectivity.
Custom Lighting and Commercial Features
Personalize your build with ASUS Aura Sync RGB and three addressable Gen 2 headers for synchronized lighting effects. ASUS GlideX and Armoury Crate software enhance control and system monitoring. With CSM support for long-term commercial deployment, a 36-month lifecycle, and ASUS Control Center Express for IT management, this board is also ideal for business. The ASUS PRIME B840M-A-CSM expertly blends power, cooling, expandability, and ease of use for professionals and gamers alike.
| Description | Specification |
|---|---|
| Motherboard Type | Desktop |
| Form Factor | Micro ATX |
| Socket | AMD AM5 |
| Chipset | AMD B840 |
| DDR Type | DDR5 |
| CPU Support | Click here for CPU support |
| RAM Technology | DDR5 (Dual Channel), ECC and Non-ECC Un-buffered DIMM*, Supports AMD EXPO, ASUS AEMP *Non-ECC, un-buffered DDR5 memory supports On-Die ECC function |
| RAM Slots | 4 x DIMM |
| RAM Speeds | Up to 7600+MT/s (OC) |
| Maximum Memory | 256GB |
| Graphics | Integrated Graphics* *Graphics specifications may vary between CPU types |
| Graphics Ports | 1 x HDMI 2 x Display Port |
| PCI/PCI Express | Ryzen 9000 & 7000 Series CPUs: 1 x PCIe 4.0 x16 (supports x16 mode) Ryzen 8000 Series CPUs: 1 x PCIe 4.0 x16 (supports x8/x4 mode) AMD B840 Chipset: 2 x PCIe 3.0 x16 (support x1 mode) |
| Storage | 4 x SATA III 3 x M.2 Ryzen 9000 & 7000 Series CPUs: M.2_1 (2280) – PCIe 4.0 x4 M.2_2 (2242/2260/2280) – PCIe 4.0 x4 Ryzen 8000 Series CPUs: M.2_1 (2280) – PCIe 4.0 x4 M.2_2 (2242/2260/2280) – PCIe 4.0 x4/x2 AMD B840 Chipset: M.2_3 (2280) – PCIe 3.0 x4 |
| RAID | AMD RAIDXpert2 Technology Ryzen 9000 Series Processors: RAID 0/1/5/10 Ryzen 8000 Series Processors: RAID 0/1 Ryzen 7000 Series Processors: RAID 0/1/10 |
| Wireless | – |
| LAN | 2.5GB LAN |
| Audio | Realtek 7.1 Surround Sound High Definition Audio CODEC |
| USB Ports Supported | Rear: 2 x USB 10Gbps Type-A 1 x USB 5Gbps Type-C 4 x USB 2.0 Front: 1 x USB 5Gbps Type-C 2 x USB 5Gbps 4 x USB 2.0 |
| Back Panel I/O Ports | 2 x USB 10Gbps Type-A 1 x USB 5Gbps Type-C 4 x USB 2.0 2 x Display Port 1 x HDMI 1 x Realtek 2.5Gb Ethernet 3 x Audio jacks 1 x BIOS FlashBack button |
| Internal I/O Connectors | 1 x 4-pin CPU Fan 1 x 4-pin CPU OPT Fan 2 x 4-pin Chassis Fan 1 x 24-pin Main 1 x 8-pin +12V CPU 3 x M.2 (Key M) 4 x SATA 6Gb/s 1 x USB 5Gbps Type-C 1 x USB 5Gbps 2 x USB 2.0 3 x Addressable Gen2 1 x Clear CMOS 1 x COM Port 1 x Front Panel Audio 1 x S/PDIF Out 1 x SPI TPM (14-1 pin) 1 x 10-1 pin Front Panel System |
| Accessories | 2 x SATA 6Gb/s cables 1 x M.2 rubber package 2 x Screw packages for M.2 SSD 1 x ACC Express Activation Key Card 1 x Quick start guide |
| Package Type | Retail |
| Package Weight | 1.4500 kg |
| Warranty | 3 Years |
Other Options
Customer Reviews
42 reviews for Asus PRIME B840M-A-CSM AMD B840 AM5 Micro ATX 4 DDR5 HDMI 2 DP 2.5G LAN 3x M.2
Clear filtersRecently viewed
- Form Factor: Micro ATX
- Socket: AMD AM5
- Chipset: AMD B840
- DDR Type: DDR5
ASUS PRIME B840M-A-CSM Ultimate Performance Micro-ATX Motherboard
Engineered for Ryzen Performance
The ASUS PRIME B840M-A-CSM is built to support AMD Ryzenâ„¢ 9000, 8000, and 7000 Series processors using the powerful AMD B840 chipset and AM5 socket. With support for blazing-fast DDR5 RAM (up to 7600+ MT/s OC), dual PCIe 4.0 x4 M.2 slots, and high-bandwidth PCIe 4.0 graphics, this motherboard is ideal for handling heavy workloads, high-end gaming, and AI applications. Realtek 2.5Gb Ethernet provides ultra-reliable, high-speed networking, while BIOS FlashBackâ„¢ allows seamless BIOS updates without a CPU or memory installed.
Advanced Cooling and Expansion Options
Cooling is handled with precision thanks to dedicated VRM and PCH heatsinks and ASUS Fan Xpert 2+ for granular fan control. A pre-mounted I/O shield and Q-LED Core diagnostics simplify installation and troubleshooting, while SafeSlot Core+ ensures GPU slot durability. Expand your storage with three M.2 slots (PCIe 4.0 and 3.0) and four SATA ports, with full RAID support under RAIDXpert2. Rear and front USB Type-C® ports (5Gbps), plus multiple USB 10Gbps and 2.0 ports, provide comprehensive device connectivity.
Custom Lighting and Commercial Features
Personalize your build with ASUS Aura Sync RGB and three addressable Gen 2 headers for synchronized lighting effects. ASUS GlideX and Armoury Crate software enhance control and system monitoring. With CSM support for long-term commercial deployment, a 36-month lifecycle, and ASUS Control Center Express for IT management, this board is also ideal for business. The ASUS PRIME B840M-A-CSM expertly blends power, cooling, expandability, and ease of use for professionals and gamers alike.
| Description | Specification |
|---|---|
| Motherboard Type | Desktop |
| Form Factor | Micro ATX |
| Socket | AMD AM5 |
| Chipset | AMD B840 |
| DDR Type | DDR5 |
| CPU Support | Click here for CPU support |
| RAM Technology | DDR5 (Dual Channel), ECC and Non-ECC Un-buffered DIMM*, Supports AMD EXPO, ASUS AEMP *Non-ECC, un-buffered DDR5 memory supports On-Die ECC function |
| RAM Slots | 4 x DIMM |
| RAM Speeds | Up to 7600+MT/s (OC) |
| Maximum Memory | 256GB |
| Graphics | Integrated Graphics* *Graphics specifications may vary between CPU types |
| Graphics Ports | 1 x HDMI 2 x Display Port |
| PCI/PCI Express | Ryzen 9000 & 7000 Series CPUs: 1 x PCIe 4.0 x16 (supports x16 mode) Ryzen 8000 Series CPUs: 1 x PCIe 4.0 x16 (supports x8/x4 mode) AMD B840 Chipset: 2 x PCIe 3.0 x16 (support x1 mode) |
| Storage | 4 x SATA III 3 x M.2 Ryzen 9000 & 7000 Series CPUs: M.2_1 (2280) – PCIe 4.0 x4 M.2_2 (2242/2260/2280) – PCIe 4.0 x4 Ryzen 8000 Series CPUs: M.2_1 (2280) – PCIe 4.0 x4 M.2_2 (2242/2260/2280) – PCIe 4.0 x4/x2 AMD B840 Chipset: M.2_3 (2280) – PCIe 3.0 x4 |
| RAID | AMD RAIDXpert2 Technology Ryzen 9000 Series Processors: RAID 0/1/5/10 Ryzen 8000 Series Processors: RAID 0/1 Ryzen 7000 Series Processors: RAID 0/1/10 |
| Wireless | – |
| LAN | 2.5GB LAN |
| Audio | Realtek 7.1 Surround Sound High Definition Audio CODEC |
| USB Ports Supported | Rear: 2 x USB 10Gbps Type-A 1 x USB 5Gbps Type-C 4 x USB 2.0 Front: 1 x USB 5Gbps Type-C 2 x USB 5Gbps 4 x USB 2.0 |
| Back Panel I/O Ports | 2 x USB 10Gbps Type-A 1 x USB 5Gbps Type-C 4 x USB 2.0 2 x Display Port 1 x HDMI 1 x Realtek 2.5Gb Ethernet 3 x Audio jacks 1 x BIOS FlashBack button |
| Internal I/O Connectors | 1 x 4-pin CPU Fan 1 x 4-pin CPU OPT Fan 2 x 4-pin Chassis Fan 1 x 24-pin Main 1 x 8-pin +12V CPU 3 x M.2 (Key M) 4 x SATA 6Gb/s 1 x USB 5Gbps Type-C 1 x USB 5Gbps 2 x USB 2.0 3 x Addressable Gen2 1 x Clear CMOS 1 x COM Port 1 x Front Panel Audio 1 x S/PDIF Out 1 x SPI TPM (14-1 pin) 1 x 10-1 pin Front Panel System |
| Accessories | 2 x SATA 6Gb/s cables 1 x M.2 rubber package 2 x Screw packages for M.2 SSD 1 x ACC Express Activation Key Card 1 x Quick start guide |
| Package Type | Retail |
| Package Weight | 1.4500 kg |
| Warranty | 3 Years |
26 reviews for Asus PRIME B840M-A-CSM AMD B840 AM5 Micro ATX 4 DDR5 HDMI 2 DP 2.5G LAN 3x M.2
Clear filters-
My FPS increased significantly after installation
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Installation was simple and quick
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Would definitely buy again from this store
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Solid quality and very quiet in operation
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Mediocre speed, suitable for casual users
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This component exceeded my expectations
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Fits well in my case, tight clearance though
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Fan gets loud during gaming
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Ran into compatibility issues at first
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Great customer support and fast dispatch
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No issues at all, plug and play with great performance
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Had some issues during installation
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Great for gaming, just not future-proof
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A must-have upgrade for any serious gamer
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Zero compatibility issues, great experience
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Massive improvement from my old component
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Average results in benchmark tests
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Good for budget builds, not for high-end use
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Perfect for gaming and multitasking
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Fair price and great service
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Highly recommend for any PC build
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Works flawlessly with my setup
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Helped speed up my PC noticeably
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No major issues, but lacks polish
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Took a while to arrive, but it works
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Performance is inconsistent under load
Obie (verified owner) –
Support was slow to respond
Philip (verified owner) –
Very stable even under heavy load
Myrtice (verified owner) –
Great for gaming, just not future-proof
Milan (verified owner) –
Good choice for mid-range builds
Mariam (verified owner) –
Great customer support and fast dispatch
Orion (verified owner) –
Strong build quality and smooth functionality
Priscilla (verified owner) –
My FPS increased significantly after installation
Nora (verified owner) –
Highly recommend for any PC build
Patience (verified owner) –
Worked as expected, a bit bulky though
Lina (verified owner) –
Fantastic price for this level of performance
Osborne (verified owner) –
Massive improvement from my old component
Noe (verified owner) –
A must-have upgrade for any serious gamer
Lela (verified owner) –
Speed boost was immediately noticeable
Pierre (verified owner) –
Super fast delivery and the product works perfectly
Megane (verified owner) –
Very efficient and stays cool
Norene (verified owner) –
Decent thermal performance, not the best
Leanna (verified owner) –
Fair quality, feels a bit outdated
Mariela (verified owner) –
Good value but no included cables
Manuel (verified owner) –
Very satisfied, just a small scratch on arrival
Niko (verified owner) –
Everything works fine, but delivery could be faster
Nicola (verified owner) –
Came with everything needed to get started
Merle (verified owner) –
This component exceeded my expectations
Neha (verified owner) –
Fair price and great service
Loy (verified owner) –
Performance is inconsistent under load
Paige (verified owner) –
Took a while to arrive, but it works
Lillie (verified owner) –
Runs fine, had to tweak settings a little
Liana (verified owner) –
Exactly as described and works great
Monte (verified owner) –
Installation was simple and quick
Magdalen (verified owner) –
It’s working, but I’ll upgrade soon
Reece (verified owner) –
Reliable, powerful, and works as expected
Miller (verified owner) –
Works great but shipping took a bit longer than expected
Ray (verified owner) –
It’s fine, just not worth the hype
Pascale (verified owner) –
Build quality is impressive, fan a bit loud
Otis (verified owner) –
Could be better for the money
Pedro (verified owner) –
Amazing value for money, my PC runs smoother than ever
Maribel (verified owner) –
Product arrived dusty but functional
Raegan (verified owner) –
Had some issues during installation
Peyton (verified owner) –
Excellent packaging and genuine product
Marina (verified owner) –
Worked after a few restarts
Odie (verified owner) –
Perfect for gaming and multitasking
Noelia (verified owner) –
Good for budget builds, not for high-end use
Murray (verified owner) –
Does the job but runs hotter than expected