MSI B850M Mortar Wi-Fi Review – The MATX AM5 Motherboard We’ve Been Waiting For

It’s a little late, but it’s finally here, the motherboard everyone’s been waiting for: The MSI B850M Mortar Wi-Fi. It’s not just the heart of your PC build, it’s the foundation that ties together design, performance, and personality. Built on the new B850 chipset and AM5 platform, this MATX board is more than just compact, it’s a no-compromise performer. Let’s dive into what it brings to the table, starting with what’s inside the box.

Unboxing the MSI B850M Mortar Wi-Fi

Inside the packaging, the first thing that greets you is MSI’s new EZ Antenna, that has a clip on feature, followed by the motherboard itself neatly tucked in place. Beneath the protective cardboard, you’ll find a set of essential accessories: the EZ Front Panel Cable for easier case-to-board cabling, an EZ Conn cable (more on that later), SATA cables, a set of EZ M.2 clips, a dedicated EZ M.2 clip remover, and of course, M.2 screws. You’ll also find the usual paperwork, but let’s be honest, we tend to skip over those anyway.

Design & Build Quality

In terms of physical dimensions, the B850M Mortar WiFi is a perfect square (243.84mmx243.84mm), true to the MATX form factor. The PCB is composed of 8 layers and includes 2oz of copper, ensuring excellent signal integrity and overall stability. MSI has equipped this board with a robust 12+2+1 power phase design, powered by 60-amp smart power stages. With dual 8-pin EPS connectors delivering up to 300W of power, this board is well-prepared to handle high-end CPUs like the Ryzen 9 9950X without breaking a sweat.

Cooling is well thought out for a motherboard this size. You get extended heatsinks over the VRMs, M.2 slots, and chipset. One of the pain points in the previous Mortar generation, the wobbly chipset heatsink, has been addressed this time around. Everything now feels solid and premium. The color scheme sticks to MSI’s Mortar/Tomahawk identity of the current generation: a stealthy mix of black and dark grey, with subtle lime-green or lemon-yellow accents.

RAM and Storage Support

The board supports up to 256GB of DDR5 memory, with maximum speeds rated at 8400MHz. That said, achieving such high frequencies depends on various factors, such as BIOS tuning, CPU IMC quality, and RAM compatibility, so don’t expect plug-and-play success with every setup. It’s best to research your memory kits and understand DDR5 behavior to push those speeds reliably.

In terms of storage, MSI gives you two front-facing M.2 slots, one supporting PCIe Gen 5 and the other Gen 4. The best part? No lane sharing here. The Gen 5 slot draws lanes directly from the CPU, while the Gen 4 one gets its bandwidth from the chipset. Both M.2 slots also benefit from MSI’s EZ M.2 shield design, making installation and removal incredibly simple, just a click away.

But that’s not all. Flip the board around and you’ll discover a third M.2 slot hidden at the rear, a clever surprise from MSI. This slot supports up to PCIe Gen 4 SSDs, but there are some caveats. First, many MATX cases don’t have dedicated cutouts for rear M.2 installation, making it tricky to access. Second, Gen 4 NVMe drives tend to run hot, and without proper airflow or heatsinks at the back, thermal throttling becomes a concern. If you must use the rear slot, a Gen 3 NVMe SSD is a better choice for cooler operation.

PCIe Slots and Power Considerations

The B850M Mortar WiFi features two PCIe expansion slots: the top one is Gen 5 x16, and the bottom is Gen 4 x4. Again, there’s no lane sharing, each slot operates independently, offering full performance whether you're installing a GPU or expansion card. The Gen 5 x 16 slot, also features MSI’s EZ PCIe Toggle (sometimes referred to as PCIe release), which makes inserting and securing your GPU more convenient. Just remember: press the toggle once before slotting in your GPU, and again afterward to lock it securely. It’s a fantastic addition that improves usability and ensures your GPU stays firmly in place.

One more thing to take note of is the supplemental PCIe power connector at the bottom of the board. It allows for an additional 252W of power delivery, which is handy if you're installing a Gen 5 GPU and multiple Gen 5 NVMe SSDs. If you're building a less extreme setup, you can probably skip this connection without worry.

Connectivity & I/O Features

Moving to the rear I/O panel, MSI has provided seven USB Type-A ports and two USB Type-C ports. While USB 4.0 is absent on this B850 board, you still get a healthy mix of USB 3.2 Gen 2 and Gen 1 ports for all your peripherals. There's also a 5Gbps Ethernet port, and HDMI output.

What I appreciate here is MSI’s thoughtful touch, they’ve printed the data rates directly on the I/O shield, which makes identifying the correct ports easier. Also present are the BIOS Flashback and Clear CMOS buttons. Each is designed with different height profiles: the taller one is Clear CMOS, and the shorter one is BIOS Flashback. This attention to detail helps avoid accidental presses and makes them easier to distinguish by feel.

Even though BIOS Flashback won’t be necessary for now as the board supports Ryzen 7000, 8000, and 9000 series processors out of the box, it’s still great to have for future upgrades, such as the potential Ryzen 10000 series. With this feature, you can update the BIOS without a CPU, simply by plugging in a USB stick with the firmware and pressing the button.

EZ Conn & Front Panel Design

MSI includes an EZ Conn cable and EZ Front Panel Connector to simplify installation. The EZ Front Panel Connector is great for achieving clean cable routing when connecting power/reset buttons and LEDs. The EZ Conn header, however, has undergone a change. On previous models like the B860M Mortar, this proprietary connector featured 11 pins, but the B850M only includes 7 pins. The missing four pins mean this header now only supports ARGB lighting connections and fans, not USB 2.0 devices.

This could be problematic if you plan on using MSI’s AIO coolers or other peripherals that require a USB 2.0 internal connection. In those cases, you’ll have to rely on a standard USB 2.0 header or use a USB expansion hub.

Final Thoughts

At RM1199, the MSI B850M Mortar WiFi may seem a little pricey for an MATX motherboard, but when you consider the features, build quality, and performance, it’s a solid value proposition. You’re getting high-end power delivery, support for the latest Ryzen processors, Gen 5 PCIe and NVMe, and thoughtful design touches that make building a system with this board a smoother experience.

Personally, I’ve always been a fan of the Mortar series. Each generation brings practical improvements without straying from the series' minimalist military-inspired aesthetic. The B850M Mortar WiFi continues that legacy, offering almost flagship-like features in a compact form factor.

This might just be the best MATX motherboard for the AM5 platform right now.  KT Media Rating: 9.1 / 10

Category	Score	Remarks
Build Quality	10	Sturdy with great thermal solutions and improved heatsinks
Power Delivery	9.0	Excellent for its class; handles Ryzen 9 CPUs effortlessly
Features & Connectivity	8.5	Gen 5 support, triple M.2 slots — just missing USB 4.0 and 10gbps connectivity
Ease of Use	9.0	EZ tools are great, but EZ Conn’s pin limitations might affect some
Aesthetics	10	Signature stealthy Mortar look, clean layout
Value For Money	8.0	On the pricier side, but justified for what you get