MSI
MSI B840M-B Gaming Desktop Motherboard - AMD B840 Chipset - Socket AM5 - Micro ATX (prob840m-b)
- SKU:
- 21245770
- MPN:
- prob840m-b
- Availability:
- Usually ships the same or next business day.
- Shipping:
- Calculated at Checkout
- Stock Update:
- 08/31/2026 03:04:44 PM PST
Bulk discount rates
Below are the available bulk discount rates for each individual item when you purchase a certain amount
| Buy 2 or above | and pay only $105.36 each 105.36 |
- Stock Update:
- 08/31/2026 03:04:44 PM PST
Description
This item is brand-new, factory sealed.
PRO B840M-B
PRO B840M-B is engineered with many exclusive features of MSI, PCIe 4.0 M.2, EZ PCIe Clip II, 2.5G LAN, and Front Type-C, ready for the AMD Ryzen™ 9000 series processors.
PRO BUSINESS ELEGANCE
The PRO Series is tailored to professionals from all walks of life. The lineup features impressive performance and high quality, while aiming to provide users incredible experience. Users who care about productivity and efficiency can definitely count on the MSI PRO Series to assist you with multitasking and increasing efficiency.
MSI motherboards are designed with advanced hardware and technology, well-supporting the demanding computing usage of gaming and AI. Moreover, we also introduce AI to MSI Center and BIOS, making everything more effortless than before.
AI Engine
provides several categories for you to sync the applications you want to perform and automatically optimizing them to create a comfortable environment.
AI LAN MANAGER
optimizes networking performance and minimizes latency, providing a seamless online experience.
Frozr AI Cooling
automatically adjusts fan duty to make sure the system stays in cool, stable and high performance.
AI Boost
is an MSI exclusive feature. It overclocks NPU to improve higher AI performance.
One Finger for EZ GPU Installation
The new EZ PCIe Clip II, located on the first slot, features the rebounding force mechanism that allows for easy removal of the graphics card by pressing the tail-like lock with one finger. Due to this exquisite design, users can uninstall the graphics cards effortlessly, even in the cramped case spaces.
Package Contents:
- PRO B840M-B Gaming Desktop Motherboard
- European Union Regulatory Notice
- Quick Installation Guide
- EZ M.2 Clip II Remover
- 2 x M.2 Clip II
- I/O Shield
- Sata Cables
Features
- PRO B840M-B Gaming Desktop Motherboard
- European Union Regulatory Notice
- Quick Installation Guide
- EZ M.2 Clip II Remover
- 2 x EZ M.2 Clip II
- I/O Shield
- SATA Cables
Brand Compatibility:
AMD
Specs
| Physical Characteristics | |
| Form Factor | Micro ATX |
| Weight (Approximate) | 2.20 lb |
| Height | 2.6" |
| Width | 9.6" |
| Depth | 8.9" |
| Warranty | |
| Additional Warranty Information | <p>3 years - Warranty period of 36 months applies on new retail MSI motherboards.</p> |
| Limited Warranty | 3 Year |
| I/O Expansions | |
| Number of PCI Express x1 Slots | 1 |
| Total Number of Expansion Slots | 2 |
| PCI Express Standard |
|
| Number of PCI Express x16 Slots | 1 |
| Total Number of PCI Express Slots | 2 |
| Memory | |
| Memory Technology | DDR5 SDRAM |
| Number of Memory Slots | 2 |
| Memory Speed Supported |
|
| Memory Form Factor |
|
| Maximum Memory Supported | 128 GB |
| General Information | |
| Brand Name | MSI |
| Manufacturer Website Address | http://www.msi.com |
| Marketing Information | PRO B840M-B PRO B840M-B is engineered with many exclusive features of MSI, PCIe 4.0 M.2, EZ PCIe Clip II, 2.5G LAN, and Front Type-C, ready for the AMD Ryzen 9000 series processors. PRO BUSINESS ELEGANCE The PRO Series is tailored to professionals from all walks of life. The lineup features impressive performance and high quality, while aiming to provide users incredible experience. Users who care about productivity and efficiency can definitely count on the MSI PRO Series to assist you with multitasking and increasing efficiency. READY FOR AI PC MSI motherboards are designed with advanced hardware and technology, well-supporting the demanding computing usage of gaming and AI. Moreover, we also introduce AI to MSI Center and BIOS, making everything more effortless than before. AI Engine provides several categories for you to sync the applications you want to perform and automatically optimizing them to create a comfortable environment. AI LAN MANAGER optimizes networking performance and minimizes latency, providing a seamless online experience. Frozr AI Cooling automatically adjusts fan duty to make sure the system stays in cool, stable and high performance. AI Boost is an MSI exclusive feature. It overclocks NPU to improve higher AI performance. |
| Product Type | Gaming Desktop Motherboard |
| Product Name | PRO B840M-B Gaming Desktop Motherboard |
| Manufacturer | MSI |
| Manufacturer Part Number | PROB840MB |
| Product Model | B840M-B |
| Product Series | PRO |
| Processor & Chipset | |
| Chipset Manufacturer | AMD |
| Processor Supported |
|
| Total Processor Supported | 1 |
| Processor Socket | Socket AM5 |
| Chipset Model | B840 |
| Technical Information | |
| AI-powered | Yes |
| Onboard Interfaces | |
| Number of SATA Interfaces | 4 |
| Total Number of Onboard USB Ports | 7 |
| Number of M.2 Interfaces | 2 |
| Number of Onboard USB 2.0 Ports | 4 |
| Interfaces/Ports | |
| VGA | Yes |
| HDMI Version | <p>2.1</p> |
| HDMI | Yes |
| Number of USB 2.0 Ports | 2 |
| Total Number of USB Ports | 6 |
| Number of Network (RJ-45) Ports | 1 |
| I/O Controller | |
| RAID Supported | Yes |
| Controller Type | Serial ATA/600 |
| RAID Levels |
|
| Video | |
| Onboard Video | CPU Dependent Video |
| Network & Communication | |
| 2.5Gigabit Ethernet | Yes |
| Gigabit Ethernet | Yes |
| Audio | |
| Audio Channels | 7.1 |
Warranty Information
