MAG B850M MORTAR
The MSI MAG B850M MORTAR is a Micro ATX AM5 motherboard on the B850 chipset. It supports DDR5 memory and 3 M.2 slots. Full specs, power delivery, and current prices are below.
Prices update regularly and may differ at the retailer. This page contains affiliate links.
MaxMyBuild scores
How we score →How well the MAG B850M MORTAR is equipped for gaming and for productivity, scored 0–100 from its specs. Scores are fit-for-purpose: a capable board can top the gaming score without being the most expensive. Each factor is judged against what AM5 processors can use, so the score compares this board with the others you could buy for the same chip.
Weighs CPU power delivery, memory speed support, the GPU PCIe slot, Wi-Fi version, and M.2 storage — the things that actually matter for a gaming build.
Rewards fast, plentiful M.2 storage and USB I/O, PCIe expansion, memory capacity and slots — what matters for content creation and heavy multitasking.
CPU power
540 W
Overbuilt · 2.3x
Wired for about 540 W, roughly 2.3x the 230 W that the top Ryzen 9 chips pull, so nothing on this socket will run it short of power. The figure comes from its 2x6+2+1 power-stage (VRM) layout and 8+8 EPS connectors. It is a rating of what the board is built to deliver, not a measurement, so treat it as headroom rather than a guarantee.
Specifications
Platform
- Chipset
- B850
- Socket
- AM5
- Form factor
- Micro ATX
- MSRP
- $190.00
Memory
- Type
- DDR5
- Slots
- 4
- Max capacity
- 256 GB
- Channels
- 2-channel
- ECC / memory
- UDIMM
Power & VRM
- CPU power
- 540 W
- Phase config
- 2x6+2+1
- VRM stages
- 60A SPS
- EPS power
- 8+8
- VRM heatsink
- Full coverage
Storage & Expansion
- M.2 slots
- 3
- M.2 layout
- 2× PCIe 5.0 ×4, 1× PCIe 4.0 ×2
- M.2 heatsinks
- Slots 1, 2
- SATA ports
- 4 SATA3
- PCIe ×16 slots
- 1× PCIe 5.0 ×16
- Other PCIe slots
- 1× PCIe 4.0 ×4
Ethernet & Wi-Fi
- Realtek RTL8126-VB
- 5 GbE
- Ethernet ports
- 1
- Wi-Fi
- None
USB & I/O
- Rear USB-A
- 4× 5 Gbps, 3× 10 Gbps
- Rear USB-C
- 1× 10 Gbps, 1× 20 Gbps
- Front USB-C
- 1× 20Gbps
- Front USB 3 headers
- 1
- Front USB 2 headers
- 2
Audio & Video
- Audio codec
- ALC4080
- Audio jacks
- 2
- S/PDIF out
- Yes
- HDMI
- 1 port
- DisplayPort
- None
- USB-C video
- None
Cooling, RGB & Design
- Fan headers
- 6
- 12V RGB headers
- 1
- 5V ARGB headers
- 3
- PCB colour
- Black
- Heatsink colour
- Dark Gray, Lime
Onboard & Diagnostics
- BIOS Flashback
- Yes (Rear)
- Diagnostics
- Debug LEDs
- Onboard buttons
- Clear CMOS
- Aux PCIe power
- 1 8-pin
Compare the MAG B850M MORTAR against every other board on the motherboard comparison table. Not sure it fits your chip? The socket compatibility guide explains AM5 pairings.
Where to buy the MAG B850M MORTAR
Every in-stock retailer offer we track, cheapest first.
| Retailer | Availability | Price | Updated | Buy |
|---|---|---|---|---|
| Newegg | In stock | $329.99 |  |
The MAG B850M MORTAR starts from $329.99 across 1 retailer (No onboard Wi-Fi). Prices update daily from live stock.
Which CPUs fit the MAG B850M MORTAR?
Compare all CPUs →In-stock AM5 processors this board can run, socket-matched and within its 540 W power budget, ranked by gaming value (performance per dollar).
| Processor | Cores | Gaming | From | |
|---|---|---|---|---|
| Ryzen 5 7500F AMD | 6/12 | 61.0 | $109.00 | |
| Ryzen 5 8400FOEM / tray AMD | 6/12 | 50.0 | $92.33 | |
| Ryzen 5 7400FOEM / tray AMD | 6/12 | 54.2 | $105.73 | |
| Ryzen 7 7700OEM / tray AMD | 8/16 | 68.5 | $138.39 | |
| Ryzen 5 7600XOEM / tray AMD | 6/12 | 67.3 | $138.38 | |
| Ryzen 5 9600X AMD | 6/12 | 72.6 | $172.55 | |
| Ryzen 5 8500G AMD | 6/12 | 52.0 | $138.37 | |
| Ryzen 7 8700FOEM / tray AMD | 8/16 | 57.3 | $177.35 Free shipping |
OEM / tray is the bare processor: no retail box and no cooler in the package, and the warranty is handled by the seller. The chip itself is the same.
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