MSI MAG B650M MORTAR WIFI Upgrade Guide: RAM, SSD and CPU

Lifecycle and support

A current model: sold new and supported.

Dates not listed haven't been published by the manufacturer or a reliable third party.

RAM: four DDR5 slots, dual channel

The board has four full-size DDR5 DIMM slots (DIMMA1, DIMMA2, DIMMB1, DIMMB2) running in dual channel. Only non-ECC, unbuffered modules work, and DDR4 or laptop SO-DIMMs will not fit. AMD EXPO profiles are supported. There is no soldered memory, so everything is upgradeable.

MSI's spec page lists up to 256 GB in total, but the manual says up to 128 GB and points to MSI's compatibility list. MSI doesn't state a per-module maximum; 256 GB across four slots implies 64 GB modules. Check MSI's memory compatibility list before buying 4 x 64 GB.

The standard (JEDEC) speed is 4800 MT/s. Faster speeds are overclocks and are not guaranteed. MSI lists up to 7600+ MT/s with one single-rank module per channel, 6400+ MT/s with one dual-rank module per channel or two single-rank modules per channel, and 5400+ MT/s with two dual-rank modules per channel. Filling all four slots lowers the speed you can reach. Some modules also run below their rated speed until you set the DRAM frequency in the BIOS.

Buying tips

• For two modules, buy a matched pair and install the first in DIMMA2.
• For dual channel, use modules of the same type, number and density.
• Two larger modules usually give better speeds than four smaller ones.
• Look for an EXPO kit and check MSI's compatibility list.
• If you fill all four slots or overclock, MSI recommends better memory cooling.

Storage: two M.2 slots plus six SATA ports

Both M.2 slots (M.2_1 and M.2_2) are Key M and connect directly to the CPU at up to PCIe 4.0 x4 for NVMe SSDs. They take 2260 and 2280 drives only. 2230, 2242 and 22110 drives do not fit. A 2260 drive needs the supplied EZ M.2 Clip. If your SSD comes with its own heatsink, remove the board's M.2 heatsink plates or rubber cubes first. MSI doesn't say whether the M.2 slots accept SATA-mode drives, so stick with NVMe.

The board also has six SATA 6Gb/s ports. Two pairs (SATA_1_2 and SATA_3_4) come from the B650 chipset, and SATA_A1 and SATA_A2 come from a separate ASM1061 controller. RAID is supported on the chipset SATA ports (0, 1 and 10) and across M.2 NVMe drives (0 and 1), but not on the SATA_A1 and SATA_A2 ports. MSI gives no maximum capacity for any drive.

The board has no drive bays. How many 2.5 inch or 3.5 inch drives you can mount depends on your case.

Buying tips

• Buy a PCIe 4.0 NVMe drive in 2280 size; a PCIe 5.0 drive would run at 4.0 speeds here.
• Avoid 2230, 2242 and 22110 drives.
• If the SSD has its own heatsink, you'll remove the board's M.2 heatsink.
• Check your case for 2.5 inch or 3.5 inch bays before buying SATA drives.
• Using a Ryzen 8500G or 8300G? Plan around M.2_2 possibly not working.

CPU: Socket AM5, Ryzen 7000, 8000G and 9000

The processor sits in a socket and can be swapped. It is an AM5 socket with the AMD B650 chipset. MSI lists Ryzen 7000, 8000 and 9000 series desktop processors. Older launch documents listed only Ryzen 7000, with the later families added through BIOS updates. Treat 170 W as the practical power ceiling. The board has a 12+2 phase power design with dual 8-pin CPU power connectors. MSI's documents don't name which individual models it has validated.

Check the BIOS first. A Ryzen 9000 chip may need a BIOS update before the board will start. MSI's per-CPU minimum BIOS list is on the board's support page. Update with M-FLASH, using a CPU the board already supports, because a flashback option isn't mentioned in MSI's documents.

Watch the cheaper APUs. Ryzen 8500 and 8300 chips make the M.2_2 slot unavailable. MSI's spec page names the 8500 and 8300 series, while the manual names only the Ryzen 5 8500G, so treat any 8000G chip as a risk. 8000-series chips also have fewer PCIe lanes: the graphics slot runs x8 with the 8700, 8600 and 8400, and x4 with the 8500 and 8300. Onboard video outputs only work with a CPU that has integrated graphics. You also need a cooler, as MSI says a heatsink is mandatory.

Buying tips

• Check MSI's CPU support list for the minimum BIOS version before buying.
• If you're buying a Ryzen 9000 chip, plan the BIOS update first.
• Stay at or under 170 W.
• Pick a Ryzen 7000 or 9000 chip if you want the full PCIe layout and both M.2 slots.
• Need onboard video? Choose a CPU with integrated graphics.
• Keep the socket's protective cap; MSI accepts RMA requests only if the board returns with it fitted.

How to upgrade

Before you start

• Back up important files.
• Check MSI's memory compatibility list and CPU support list for the part you plan to buy.
• If you're fitting a newer Ryzen chip, update the BIOS with M-FLASH first, using a CPU the board already supports.
• Have the owner's manual to hand for exact layout and disassembly details.
• Gather the supplied EZ M.2 Clip if you're fitting a 2260 SSD.

Steps

1. Back up and prepare
   Back up your data and note any BIOS settings you've changed. Changing the processor can clear the system configuration and reset the BIOS to defaults.
2. Power off and unplug
   Shut down the PC, switch off the power supply and unplug the power cord. Hold the power button briefly to discharge any leftover charge.
3. Ground yourself
   Touch bare metal on the case or wear an anti-static strap. Handle parts by their edges.
4. Open the case
   Remove the side panel and lay the PC down if that makes the board easier to reach. See the owner's manual for the board layout.
5. Install the RAM
   Fit the first module in DIMMA2, then add the second to match for dual channel. Press each module in until it is fully seated. Use modules of the same type, number and density.
6. Install the M.2 SSD
   Remove the board's M.2 heatsink if your SSD has its own. Slot the drive into M.2_1 or M.2_2 and secure it. A 2260 drive needs the supplied EZ M.2 Clip. Refit the heatsink if you removed one and the SSD has none.
7. Install the CPU
   Line up the triangle marker on the CPU with pin 1 on the AM5 socket and fit it as the manual describes. Keep the socket's protective cap. Apply thermal paste evenly if needed and fit the heatsink or cooler.
8. Close up and reconnect
   Refit the side panel, reconnect power and any cables, and switch the power supply back on.
9. Check the BIOS
   Press Del at startup to enter the BIOS. Confirm it shows the new RAM capacity, the SSD and the CPU. Set the DRAM frequency or enable EXPO if your memory runs below its rated speed.

Good to know

• Most detailed memory and storage specs come from the documents for the non-WiFi MAG B650M MORTAR, which appear to match the WiFi board. The WiFi manual confirms 4 DIMM slots and 2 M.2 slots.
• MSI's spec page says 256 GB maximum RAM, but the manual says 128 GB. Check MSI's compatibility list before buying 4 x 64 GB.
• MSI doesn't state a maximum size per memory module.
• Memory speeds above 4800 MT/s are overclocks and depend on your CPU, modules and how many slots are filled.
• MSI's documents don't say whether the M.2 slots accept SATA-mode drives.
• MSI's documents don't confirm which individual 170 W CPUs have been validated.
• The minimum BIOS version for each CPU isn't listed here; check MSI's CPU support list.

Frequently asked questions

How much RAM can the MSI MAG B650M MORTAR WIFI take?

MSI's spec page says up to 256 GB across four DDR5 slots, but the manual says 128 GB and points to MSI's compatibility list. Check that list before buying four 64 GB modules.

Does the MAG B650M MORTAR WIFI support DDR4?

No. It takes DDR5 only, in four full-size DIMM slots, and only non-ECC unbuffered modules.

How many M.2 SSDs does it support?

Two. Both are PCIe 4.0 x4 NVMe slots connected to the CPU and take 2260 or 2280 drives. 2230, 2242 and 22110 drives do not fit.

Can I use a Ryzen 9000 CPU?

Yes, MSI lists Ryzen 9000 support, but the board may need a BIOS update first. Check MSI's CPU support list for the minimum BIOS version.

Why is my second M.2 slot not working?

Ryzen 8500 and 8300 APUs disable M.2_2. MSI's spec page names the 8500 and 8300 series, while the manual names only the Ryzen 5 8500G.

What is the fastest RAM speed it supports?

The standard speed is 4800 MT/s. MSI lists overclocked speeds up to 7600+ MT/s with one single-rank module per channel. Speeds drop with more modules or dual-rank modules, and are not guaranteed.

Official documents and references

• MSI spec page (MAG B650M MORTAR)
  Memory speeds, M.2 and CPU details
• PDF MSI manual (MAG B650M MORTAR)
  Installation steps and M-FLASH instructions
• PDF MSI manual (MAG B650M MORTAR WIFI)
  The WiFi model's official manual
• MSI support page (MAG B650M MORTAR WIFI)
  CPU support list and BIOS downloads
• MSI spec page (WIFI model)
  Supported Ryzen series and chipset
• MSI product page (MAG B650M MORTAR WIFI)
  Cooling and power features