ASUS
ASUS Prime B840M-A CSM AM5 Micro-ATX Motherboard
In stock
SKU PRIME B840M-A-CSM
R 2 399,00
Or pay in up to 6 interest-free instalments from R 399,83 with Stitch Pay Later.
Courier delivery R180 (free on orders of R2 500 or more): 1–3 working days to Johannesburg, Pretoria, Cape Town, Durban and within 100km of them, 2–4 working days further out. Express 1–2 working days for R210 (R150 on orders of R2 500 or more).
| Delivering to | Time | Cost |
|---|---|---|
| Major centres: Johannesburg, Pretoria, Cape Town, Durban and within 100km of them | 1–3 working days | R180, free from R2 500 |
| More than 100km from a major centre | 2–4 working days | R180, free from R2 500 |
| Express delivery, anywhere | 1–2 working days | R210, R150 from R2 500 |
| Collect from Edenvale | When we tell you it’s ready | Free |
- Courier delivery is R180 on orders under R2 500 and free on orders of R2 500 or more. Choose express or collection at checkout.
- Times count from the day your order is dispatched. Orders placed before 12:00 on a working day ship the same day; after 12:00, on weekends or on public holidays they ship the next working day.
- Pre-built PCs and PC Builder builds need 2–4 extra working days to assemble and test before they ship.
- The area check is a guide based on your postal code, and delivery times are the courier’s estimates. Please make sure your address and postal code are correct — an incorrect address delays delivery.
- Full shipping policy
- Free courier delivery over R2 500 Anywhere in South Africa. R180 on orders under R2 500
- Official warranty Local South African warranty and support
- Expert help Talk to a builder before you buy
AM5 for the machines that just have to work, every day, for years
Quick Specs
- AMD B840 chipset on Socket AM5 for Ryzen 7000, 8000 and 9000 series processors
- Four DDR5 DIMM slots, dual channel, up to 128GB with AMD EXPO support
- PCIe 4.0 x16 graphics slot on a Micro-ATX board
- Two M.2 sockets for NVMe storage plus four SATA 6Gb/s ports
- Corporate Stable Model board with 2.5 Gigabit Ethernet and rear USB-C
Fleet-grade stability on a current socket
CSM boards are built for the buyer who cares more about consistency than features. ASUS commits to longer availability and controlled firmware revisions on this range, which is exactly what you want when you are specifying twenty identical machines for an office or a lab and you need number twenty to match number one. That same discipline benefits home builders who simply want a system they can set up once and forget. On AM5 it also means a long CPU upgrade path, so an office fleet built on Ryzen 7000 today can take newer chips later without new boards.
What it is not
This is a working board, not an enthusiast one. There is no onboard Wi-Fi or Bluetooth, so budget for cabling or an adapter. The graphics slot is PCIe 4.0 rather than 5.0 and Gen5 NVMe support is limited on B840, and CPU overclocking control is narrower than on B650 or B850. Lighting is minimal, there is no post-code display, and rear I/O is functional rather than lavish. If you are building a high-end gaming machine with a Ryzen 9 and want tuning headroom and wireless in the box, choose a B850 or X870 board instead.
FEATURES:
- ASUS Corporate Stable Model programme for extended availability and firmware consistency
- Four DDR5 slots with AMD EXPO one-click memory profiles
- Two M.2 sockets for NVMe storage with Q-Latch tool-free mounting
- 2.5 Gigabit Ethernet for fast local network transfers
- Comprehensive UEFI BIOS with Fan Xpert control and manageability-friendly settings
SPECIFICATIONS:
- Model: ASUS Prime B840M-A CSM
- Chipset: AMD B840
- Socket: AMD Socket AM5
- Form Factor: Micro-ATX
- Memory: 4 x DDR5 DIMM, dual channel, up to 128GB, AMD EXPO overclocked profile support
- Expansion Slots: 1 x PCIe 4.0 x16, plus additional PCIe slots for add-in cards
- Storage: 2 x M.2 sockets for PCIe NVMe SSDs, 4 x SATA 6Gb/s ports
- Networking: 2.5 Gigabit Ethernet LAN
- Audio: Realtek HD audio codec with rear audio jacks
- Rear I/O Highlights: HDMI and DisplayPort output for Ryzen integrated graphics, 2.5G LAN and audio jacks
- USB: USB 3.2 Gen2 Type-C and Type-A plus USB 3.2 Gen1 and USB 2.0 rear ports, with front-panel USB headers
- Warranty: 3 Year
WHAT'S IN THE BOX:
- ASUS Prime B840M-A CSM motherboard
- 2 x SATA data cables
- M.2 Q-Latch package and mounting screws
- Rear I/O shield
- User manual and support documentation
Why ASUS?
The CSM programme is ASUS putting its name to consistency, which is the quality that matters most when a machine has to run unattended for years. Every ASUS motherboard from AZonline is genuine stock carrying a 3 Year warranty.
Key details
| Socket | AM5 |
|---|---|
| Chipset | B840 |
| Form factor | Micro-ATX |
| Memory type | DDR5 |
| DIMM slots | 4 |
| Maximum memory | 128 GB |
| Category | Motherboards |
| Brand | ASUS |
| Warranty | 3 Years |
Questions
Before you buy
Which processors fit this board?
It takes AM5 processors on the B840 chipset. Socket and chipset together decide what will run: the socket has to match physically, and the chipset decides which generations on that socket are supported. For a chip released after the board, check the manufacturer’s CPU support list to see whether a BIOS update is needed first.
Which cases will this board fit?
It is Micro-ATX. A case supports its own size and anything smaller - an ATX case takes ATX, Micro-ATX and Mini-ITX boards, a Micro-ATX case takes Micro-ATX and Mini-ITX. Each case we sell lists the board sizes it accepts under Specifications.
What memory does it take?
DDR5 across 4 slots, up to 128GB in total. DDR4 and DDR5 are not interchangeable - the notch in the module is in a different place, so the wrong type will not seat. Buy the memory as a matched kit rather than as single sticks wherever you can.
Is it in stock, and when will it ship?
Yes - this one is in stock. Order before 12:00 on a working day and it ships the same day; after that it goes out the next working day. We are open 09:00 to 16:30, Monday to Friday, so an order placed over a weekend or a public holiday ships on the next working day.
What does delivery cost, and how long does it take?
We deliver by courier anywhere in South Africa, and delivery is R180 on orders under R2 500 and free on orders of R2 500 or more. It takes 1-3 working days to Johannesburg, Pretoria, Cape Town, Durban and areas within 100km of them, and 2-4 working days to areas more than 100km from a major centre, counted from the day the order is dispatched. Need it sooner? Express delivery is 1-2 working days for R210, or R150 on orders of R2 500 or more - choose it at checkout. We do not ship outside South Africa.
Can I collect instead of having it delivered?
Yes. Collection is from 11 Voortrekker Avenue, Edenvale, Gauteng, by arrangement - message us first so we can have the order picked and waiting. We are open 09:00 to 16:30, Monday to Friday.
What warranty does it carry, and how do I claim?
The warranty period for this product is listed at the end of the Specifications section above. Claims go through us, not the manufacturer - contact us with your order number and a description of the fault and we will handle it from there. Separately from any warranty, the Consumer Protection Act gives you six months from delivery to return goods that are defective, unsafe or not fit for their intended purpose.
What if I change my mind?
You have 14 days from delivery to change your mind - longer than the seven days the Electronic Communications and Transactions Act requires. The item needs to be unused and in its original packaging, and we pay the return shipping. Refunds go back to the payment method you used, within 30 days of the return reaching us.
How can I pay?
Payments are processed by Stitch. At the last step of checkout you are taken to Stitch’s secure page to pay, and brought back here once it is done. Your card details are entered on Stitch’s secure, PCI-compliant page and never touch our systems.
Something not covered here? Read the full FAQ, or WhatsApp us on 079 491 0181.
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