ASUS PRIME B850M-A-CSM mATX Motherboard | AM5 | 4x DDR5 Slots
KEY FEATURES
- AMD Socket AM5 AMD Ryzen 7000 Series, AMD Ryzen 8000 Series, AMD Ryzen 9000 Series
- PC micro ATX AMD B850 7.1 channels
- DDR5-SDRAM 4 DIMM Maximum internal memory: 256 GB
- HDD & SSD PCI Express 4.0, PCI Express 5.0 RAID support Number of storage drives supported: 7
- BIOS type: UEFI AMI 256 Mbit
- 2.5 Gigabit Ethernet
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Frequently Asked Questions
ASUS PRIME B850M-A-CSM mATX Motherboard | AM5 | 4x DDR5 Slots
Description
The ASUS PRIME B850M-A-CSM is a micro ATX motherboard built around AMD's B850 chipset and AM5 socket, designed for current and future Ryzen processors including the 7000, 8000, and 9000 series. This mainstream board fits well in compact builds where space is limited but performance remains important. The B850 chipset provides a solid balance of features without the premium cost of higher-tier options, making it suitable for gaming builds, productivity workstations, and general-purpose systems.
Memory support is comprehensive with four DDR5 DIMM slots accommodating up to 256GB of system RAM, with speeds reaching 8000MHz when using compatible modules and enabling memory profiles like EXPO. Storage connectivity is generous with four M.2 slots total-one PCIe 5.0 slot for the fastest NVMe drives available, plus three additional PCIe 4.0 M.2 slots for ample high-speed storage expansion. The board includes three PCIe x16 slots (one Gen 5, two Gen 4) for graphics cards and expansion cards, along with integrated Realtek 2.5 Gigabit Ethernet for fast network connectivity.
RGB enthusiasts will appreciate the three RGB LED pin headers that work with ASUS Aura Sync lighting ecosystem, while the ECC memory compatibility adds flexibility for users requiring error-correcting memory modules. The package includes mounting screws and an I/O shield for straightforward installation. BIOS FlashBack support allows firmware updates without a CPU installed, and ASUS Control Center Express provides software-based system monitoring and tweaking capabilities once your build is complete.
Feature
Easy 14 days Returns
Eligible for Next day Delivery
100% Money-back guarantee
Reliable Customer Support
Secure payment method
Shipping Information
- Next Business Day: £6.99
- 2 days Delivery: £4.99
- 3- 5 Days Shipping: £3.99
- Orders Over £99.00: Free Standard Delivery
| Processor | |
|---|---|
| Processor manufacturer | AMD |
| Processor socket | Socket AM5 |
| Compatible processor series | AMD Ryzen 7000 Series, AMD Ryzen 8000 Series, AMD Ryzen 9000 Series |
| Supported processor sockets | Socket AM5 |
| Memory | |
|---|---|
| Supported memory types | DDR5-SDRAM |
| Number of memory slots | 4 |
| Memory slots type | DIMM |
| Memory channels | Dual-channel |
| ECC сompatibility | ECC & Non-ECC |
| Supported memory clock speed (max) | 8000 MHz |
| Maximum internal memory | 256 GB |
| Unbuffered memory | Yes |
| Maximum internal memory per slot | 64 GB |
| Storage controllers | |
|---|---|
| Supported storage drive types | HDD & SSD |
| Supported storage drive interfaces | PCI Express 4.0, PCI Express 5.0 |
| Number of storage drives supported | 7 |
| Number of HDDs supported | 4 |
| RAID support | Yes |
| RAID levels | 0, 1, 5, 10 |
| Graphics | |
|---|---|
| Parallel processing technology support | Not supported |
| Maximum resolution | 7680 x 4320 pixels |
| Internal I/O | |
|---|---|
| USB 2.0 connectors | 2 |
| USB 3.2 Gen 1 (3.1 Gen 1) connectors | 2 |
| Number of SATA III connectors | 4 |
| S/PDIF out connector | Yes |
| Front panel audio connector | Yes |
| Front panel connector | Yes |
| ATX Power connector (24-pin) | Yes |
| CPU fan connector | Yes |
| Number of CPU fan connectors | 1 |
| Number of chassis fan connectors | 3 |
| Chassis intrusion connector | Yes |
| Peripheral (Molex) power connectors (4-pin) | 1 |
| EPS power connector (8-pin) | Yes |
| Number of EPS power connectors (8-pin) | 1 |
| 12V power connector | Yes |
| TPM connector | Yes |
| Number of COM connectors | 1 |
| RGB LED pin header | Yes |
| Number of RGB LED pin headers | 3 |
| Rear panel I/O ports | |
|---|---|
| USB 2.0 ports quantity | 4 |
| USB 3.2 Gen 1 (3.1 Gen 1) Type-A ports quantity | 2 |
| USB 3.2 Gen 2 (3.1 Gen 2) Type-A ports quantity | 2 |
| Ethernet LAN (RJ-45) ports | 1 |
| HDMI ports quantity | 1 |
| HDMI version | 2.1 |
| DisplayPorts quantity | 2 |
| DisplayPort version | 1.4 |
| Line-in | Yes |
| Headphone outputs | 1 |
| Microphone in | Yes |
| Network | |
|---|---|
| Ethernet LAN | Yes |
| Ethernet interface type | 2.5 Gigabit Ethernet |
| Wi-Fi | No |
| Top Wi-Fi standard | Not available |
| Features | |
|---|---|
| Component for | PC |
| Motherboard form factor | micro ATX |
| Motherboard chipset family | AMD |
| Motherboard chipset | AMD B850 |
| Audio output channels | 7.1 channels |
| Product colour | Grey |
| Power source type | ATX |
| Cooling type | Passive |
| Windows operating systems supported | Windows 10 x64, Windows 11 |
| Expansion slots | |
|---|---|
| PCI Express x16 (Gen 4.x) slots | 2 |
| PCI Express x16 (Gen 5.x) slots | 1 |
| Number of M.2 (M) slots | 3 |
| 1st M.2 largest key size | 2280 |
| 1st M.2 highest PCI Express generation | 5.0 |
| 2nd M.2 largest key size | 2280 |
| 2nd M.2 highest PCI Express generation | 4.0 |
| 3rd M.2 largest key size | 2280 |
| 3rd M.2 highest PCI Express generation | 4.0 |
| 4th M.2 largest key size | 2280 |
| 4th M.2 highest PCI Express generation | 4.0 |
| BIOS | |
|---|---|
| BIOS type | UEFI AMI |
| BIOS memory size | 256 Mbit |
| Packaging data | |
|---|---|
| Package width | 275 mm |
| Package depth | 275 mm |
| Package height | 67.5 mm |
| Package weight | 1.45 kg |
| Weight & dimensions | |
|---|---|
| Width | 244 mm |
| Depth | 244 mm |
| Packaging content | |
|---|---|
| Screws included | Yes |
| Cables included | SATA |
Frequently Asked Questions
When will it arrive?
Any order over £99 wil be shipped on our free 2-3 working day service, if you opt for Next Working Day shipping then this will be with you the next working day between 09:00 and 18:00. Deliveries to Northern Ireland, Channel Islands and the Scottish Highlands will be on a 3 day service.
Do you offer a credit account?
We offer credit accounts to Gotraka Business customers, please enquire with our customer support team for more information. Credits accounts are subject to KYC.
How long is the returns policy?
For most products bought online, you have a legal right to change your mind within 14 days and receive a refund. If you wish to return unwanted products, you must let us know that you want to return them within 14 calendar days from the day after delivery. The item must also be returned to us within 7 working days from approval of return and receipt of the return label.
How long will it take to receive my order?
This is something that we are working hard to bring to you - we recognise that having deliveries on preferred days not only makes it easier for you but it is also great for the environment. By having deliveries arranged on days that you are going to be in or consolidating your orders to arrive to you at the same time means that the courier won't need to come back multiple times due to missed deliveries or multiple deliveries.
Can I change my delivery address once the order has been placed?
Our systems are highly automated, where possible we will do our utmost to accommodate this. To ensure we maintain a high delivery success rate most of our orders are picked and prepped for shipment within 30 minutes
How do I return my order?
If you need to return your order please raise a return through your order page detailing the reason for return. Once this form has been submitted it will be reviewed by the Returns Department who will contact you to arrange the return.
Please note the returns department may ask for more information such as the serial number(s) and images where applicable to process the return.
How long do I have to return an item?
For most products bought online, you have a legal right to change your mind within 14 days and receive a refund. If you wish to return unwanted products, you must let us know that you want to return them within 14 calendar days from the day after delivery. The item must also be returned to us within 7 working days from approval of return and receipt of the return label
Are returns free?
Returns for faulty / damaged items will be free of charge
Returns for unwanted items that have no fault will incur a minimal returns fee - delivery charges will not be refunded
Can’t find what you’re looking for?
Our friendly support team is just a message away, ready to assist with anything. Our team is experienced with gaming gear, home tech, and everything in between—feel free to reach out.
📧 Email: help@gotraka.com
📞 Phone: 020 8208 1234
💬 Live Chat: Available 9 AM – 6 PM ( Monday - Friday )
