# Motherboard ASRock B850 Pro-A — AMD B850 chipset, Socket AM5, ATX, 4× DDR5 DIMM, 256 GB, 4× M.2, PCIe 5.0 x16, 2.5Gb LAN

**URL:** https://aio.lv/en/product--asrock-90-mxbqm-a0uayz--11247608
**Data updated:** 2026-01-21 11:08 (EET)
**Category:** Motherboards
**Manufacturer:** ASROCK
**Manufacturer code:** 90-MXBQM-A0UAYZ
**EAN:** 4711581490185
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 147.49 €
**Prices and availability valid until:** 2026-08-08 23:59
**Price without VAT (21%):** 121.89 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--asrock-90-mxbqm-a0uayz--11247608

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 23.07.2026 | free |
| Pickup points | 28.07.2026 | 1.89 EUR |
| Courier delivery to door | 28.07.2026 | 4.99 EUR |

## Summary description

ASRock B850 Pro-A is an ATX motherboard with AMD B850 chipset for Socket AM5 processors (AMD Ryzen 7000 series). It supports up to 256 GB DDR5 memory across 4 DIMM slots (dual-channel, ECC & non‑ECC), four M.2 slots (PCIe 5.0/4.0/3.0), one PCIe 5.0 x16 slot, RAID, 2.5 Gigabit Ethernet (Dragon RTL8125BG), Realtek ALC897 7.1 audio, HDMI 2.1, multiple USB ports including USB‑C, and fan/water pump headers for custom cooling.

## Long description

The Asrock B850 Pro-A AMD B850 Socket AM5 ATX is a full-size ATX motherboard engineered for AMD Socket AM5 processors, compatible with Ryzen 7000, 8000 and 9000 series. It supports DDR5 memory up to 256 GB across four DIMM slots and offers a variety of storage interfaces including PCIe Gen5, Gen4, Gen3 M.2 and SATA III. The board integrates an optimized power delivery system and multi-layer PCB to deliver stable performance for everyday computing, content creation and gaming.
Advantages
This motherboard features a 14+2+1 power phase VRM design with Dr.MOS integrated power stages for efficient and smooth CPU power delivery, enabling better thermal performance and stable overclocking. An 8-layer PCB improves signal integrity and energy efficiency for memory overclocking. High-speed storage options include a PCIe Gen5 Blazing M.2 slot and Hyper M.2 Gen4 x4 support. Cooling-focused elements such as aluminum heatsinks, intelligent PWM/DC fan headers and Fan-Tastic Tuning help maintain low temperatures and quiet operation. Connectivity is broadened with a Dragon 2.5 Gb/s LAN and front-panel USB 3.2 Gen2x2 Type-C header. Built-in RGB headers and SignalRGB support enable system lighting customization, while reinforced PCIe steel slots and BIOS Flashback add durability and ease of use.
Suitable for
Desktop systems for gaming and multimedia
Content creation and productivity workstations
Systems requiring fast NVMe storage and high-speed networking
Enthusiast builds with DDR5 memory and moderate overclocking
Key specifications
Form factor: ATX
Chipset: AMD B850
CPU socket: Socket AM5 (supports Ryzen 7000/8000/9000 series)
Memory: 4 x DDR5 DIMM slots, up to 256 GB, Intel XMP / AMD EXPO support
Storage: PCIe Gen5 M.2 (Blazing M.2), PCIe Gen4 M.2 (Hyper M.2 Gen4 x4), SATA III
LAN: Dragon 2.5 Gb/s Ethernet
USB: Front-panel USB 3.2 Gen2x2 Type-C header, USB Type-C with DP-alt mode
Power delivery: 14+2+1 phase VRM with Dr.MOS and Hi-Density power connector
How to use
Install the motherboard into an ATX-compatible case and connect a compatible AM5 CPU, DDR5 memory modules, storage devices (M.2 or SATA) and a suitable power supply using the Hi-Density power connector and standard ATX power cables. Use the reinforced PCIe 5.0 slot for a graphics card if required. Connect case fans to the PWM/DC headers and configure fan curves with the Fan-Tastic Tuning utility in the provided ASRock software. Update or flash the BIOS using BIOS Flashback if needed before first boot to ensure CPU and memory compatibility.
Usage recommendations
For stable overclocking and long-term reliability, use high-quality DDR5 modules that support Intel XMP or AMD EXPO profiles, ensure adequate case ventilation and use the onboard heatsinks and fan control features to keep VRM and storage temperatures low. When performing major BIOS updates, follow ASRock instructions and use a reliable USB drive and stable power source.

## Specifications

### Features

| Feature | Value |
|---|---|
| Motherboard form factor | ATX |
| Motherboard chipset | AMD B850 |
| Component for | PC |
| Certification | FCC, CE, ErP/EuP |
| Audio output channels | 7.1 |
| Windows operating systems supported | Windows 11 x64, Windows 10 x64 |
| Motherboard chipset family | AMD |

| Feature | Value |
|---|---|
| Product colour | Black |

### Processor

| Feature | Value |
|---|---|
| Processor manufacturer | AMD |
| Processor socket | Socket AM5 |

### Memory

| Feature | Value |
|---|---|
| Number of memory slots | 4 |
| Maximum internal memory | 256 GB |
| Supported memory types | DDR5-SDRAM |
| Memory channels | Dual-channel |
| Unbuffered memory | Yes |
| Memory slots type | DIMM |
| ECC сompatibility | ECC & non-ECC |

### Expansion slots

| Feature | Value |
|---|---|
| Number of M.2 (M) slots | 4 |
| PCI Express x16 (Gen 4.x) slots | 1 |
| PCI Express x16 (Gen 5.x) slots | 1 |
| 1st M.2 largest key size | 2280 |
| 2nd M.2 largest key size | 2280 |
| 3rd M.2 largest key size | 2280 |
| 4th M.2 largest key size | 2280 |
| 1st M.2 highest PCI Express generation | 5.0 |
| 2nd M.2 highest PCI Express generation | 4.0 |
| 3rd M.2 highest PCI Express generation | 4.0 |
| 4th M.2 highest PCI Express generation | 3.0 |

### Graphics

| Feature | Value |
|---|---|
| Maximum resolution | 3840 x 2160 |
| Parallel processing technology support | Not supported |
| HDCP | Yes |

### Network

| Feature | Value |
|---|---|
| Ethernet LAN | Yes |
| LAN controller | Dragon RTL8125BG |
| Wi-Fi | No |
| Ethernet interface type | 2.5 Gigabit Ethernet |

### Internal I/O

| Feature | Value |
|---|---|
| USB 2.0 connectors | 2 |
| CPU fan connector | Yes |
| ATX Power connector (24-pin) | Yes |
| Number of chassis fan connectors | 4 |
| Front panel audio connector | Yes |
| TPM connector | Yes |
| EPS power connector (8-pin) | Yes |
| USB 3.2 Gen 1 (3.1 Gen 1) connectors | 1 |
| Number of SATA III connectors | 4 |
| 12V power connector | Yes |
| RGB LED pin header | Yes |
| USB 3.2 Gen 2x2 connectors | 1 |
| Number of RGB LED pin headers | 4 |
| Number of CPU fan connectors | 2 |
| Number of water pump connectors | 1 |
| Number of EPS power connectors (8-pin) | 2 |

### Rear panel I/O ports

| Feature | Value |
|---|---|
| Line-in | Yes |
| USB connector type | USB Type-C, USB Type-A |
| USB 2.0 ports quantity | 6 |
| Ethernet LAN (RJ-45) ports | 1 |
| Headphone outputs | 3 |
| Microphone in | Yes |
| HDMI ports quantity | 1 |
| HDMI version | 2.1 |
| USB 3.2 Gen 1 (3.1 Gen 1) Type-A ports quantity | 4 |
| USB 3.2 Gen 1 (3.1 Gen 1) Type-C ports quantity | 1 |
| USB 3.2 Gen 2 (3.1 Gen 2) Type-C ports quantity | 1 |

### Storage controllers

| Feature | Value |
|---|---|
| RAID levels | 10, 1 |
| Supported storage drive types | HDD & SSD |
| RAID support | Yes |
| Number of storage drives supported | 8 |
| Supported storage drive interfaces | SATA III, PCI Express 5.0, PCI Express 4.0, PCI Express 3.0 |

### BIOS

| Feature | Value |
|---|---|
| BIOS memory size | 256 Mbit |
| BIOS type | UEFI AMI |

### Weight & dimensions

| Feature | Value |
|---|---|
| Width | 305 mm |
| Depth | 244 mm |

### Other features

| Feature | Value |
|---|---|
| Supported processor sockets | Socket AM5 |
| Audio chip | Realtek ALC897 |

### Packaging content

| Feature | Value |
|---|---|
| Cables included | SATA |
| Screws included | Yes |

## FAQ

### How much does the ASRock B850 Pro-A ATX motherboard Socket AM5 cost, and is it available for purchase?

The price is 147.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 58 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 23.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay, Installment. All transactions are 100% secure and encrypted.

### Can ASRock B850 Pro-A ATX motherboard Socket AM5 be purchased with a lease?

Yes, the purchase is available both on credit and with an interest-free installment plan. Learn more about installments and credit options: https://aio.lv/en/payment#b3

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All ASROCK products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized ASROCK service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

### How can I tell if this product suits my needs?

When making a choice, we recommend paying attention to the key features: motherboard form factor, motherboard chipset, component for, processor socket, number of memory slots, maximum internal memory, supported memory types, compatibility with your devices or usage conditions, material quality, functionality, and warranty terms. These characteristics will help you determine how well the model meets your needs.

### Where can I download the instructions for ASRock B850 Pro-A ATX motherboard Socket AM5?

You can download the instructions in PDF format from the “Instructions” section on the product description page. The file contains complete information about installation, setup, and usage.

## Image

https://aio.lv/img/cache/product/11247608/65439629_large.webp