Upgrade guide: MSI MAG X870E Tomahawk Max WIFI

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, up to 256 GB

There are 4x DDR5 DIMM (UDIMM) slots - two per memory channel - and no memory is soldered to the board. DDR5 only; DDR4 will not fit or work.

Capacity: MSI quotes a maximum of 256 GB total. MSI publishes the total rather than a per-stick figure, but 256 GB across four slots points to 64 GB modules, which is worth double-checking against MSI's QVL if you want the maximum.

Type: non-ECC, unbuffered UDIMM only. ECC and registered (RDIMM) memory is NOT supported, so if you need ECC for a workstation build, this is the wrong platform. CUDIMM modules work only in clock-driver bypass mode, and MSI warns some CPUs may fail to boot with them - plain UDIMM kits are the safe choice.

Speed: the headline figure is DDR5-8400 MT/s, and that is the single-stick, single-rank best case with a Ryzen 9000 CPU. Fill all four slots and the ceiling drops to around 6400 MT/s, and you may need manual tuning. Out of the box, stock (JEDEC) speeds run 4800-5600 MT/s; AMD EXPO profiles are supported for one-click overclocking. Achievable speed depends heavily on your CPU's memory controller.

The DIMM slots have double-sided latches, so both ends of a module clip down.

Buying tips: pick a DDR5 UDIMM kit (non-ECC) at a speed your CPU actually supports rather than chasing the highest MT/s number; if you want four sticks, expect a lower speed ceiling than with two; check MSI's Memory Compatibility List on the support page for kits tested on this board.

Buying tips

• Non-ECC unbuffered DDR5 UDIMM only - ECC and RDIMM will not work.
• For maximum capacity, look at 64 GB modules (256 GB total is MSI's stated ceiling).
• Two sticks are easier to run fast than four; 8400 MT/s is a one-stick best case.
• Check MSI's QVL for guaranteed kits, and prefer plain UDIMM over CUDIMM.

Storage: four M.2 NVMe slots and four SATA ports

You get 4x M.2 slots and 4x SATA 6 Gb/s ports. All four M.2 slots are NVMe (Key M) only - SATA-protocol M.2 drives are not supported. MSI sets no capacity ceiling, so drive size is limited only by what is on the market. The board has no memory card reader.

M.2_1 (CPU-connected): takes 22110 or 2280 drives and ships with a heatsink. It runs PCIe Gen5 with Ryzen 9000/7000, and Gen4 with Ryzen 8000.

M.2_2 (CPU-connected): takes 2280 or 2260 drives and runs Gen5 (Gen4 with Ryzen 8700/8600/8400). Two big caveats. First, Ryzen 8500/8300 processors disable this slot completely. Second, M.2_2 shares its link with the rear USB4 40 Gbps ports: install a drive and both drop to x2 bandwidth. You can force the slot to x4 in the BIOS, but that disables the rear USB4 Type-C ports.

M.2_3 and M.2_4 (chipset-connected): Gen4, 2280 or 2260. These are the straightforward slots for extra SSDs. Only M.2_1 includes a heatsink - the others may need one bought separately, especially for fast Gen5/Gen4 drives.

For bulk storage there are 4x SATA 6 Gb/s ports for 2.5-inch or 3.5-inch drives; how many physically fit is up to your case. RAID is available (SATA: 0/1/10; NVMe: 0/1/5/10), but NVMe RAID 5 needs a Ryzen 9000 CPU and RAID 10 needs Ryzen 9000/7000.

Buying tips: NVMe drives in 2280 size are the common, safe bet; pick 22110 only if you specifically want the longest drive in M.2_1. If you rely on the rear USB4 ports, think twice about filling M.2_2 at full width. And remember your CPU choice can switch slots off entirely.

Buying tips

• Buy NVMe (Key M) M.2 drives in 2280 or 2260; SATA M.2 drives will not work.
• 22110 drives fit only in M.2_1.
• Budget for a heatsink if you fill the slots that lack one.
• Avoid Ryzen 8500/8300 if you want M.2_2 working at all.

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

The processor sits in Socket AM5 (LGA-1718), one CPU per board, and is fully user-replaceable. Supported families are AMD Ryzen 7000, Ryzen 8000G and Ryzen 9000 desktop processors.

Power: MSI does not state a numeric TDP limit, but the board has 2x 8-pin CPU power connectors and the X870E VRM is designed for 170 W parts such as the 9950X and 7950X. That 170 W figure is a platform expectation rather than a published limit - check MSI's CPU support list before pairing a particularly exotic high-power chip. The BIOS offers a 65 W ECO mode plus PBO thermal profiles if you want to run cooler or quieter.

Your CPU choice also shapes what your storage can do. Ryzen 8500/8300 disable M.2_2 entirely and cut the graphics slot to Gen4 x4, and Ryzen 8000 APUs run the CPU-connected M.2 slots at Gen4 only. A Ryzen 9000 or Ryzen 7000 chip gives you all four M.2 slots at their best speeds.

One software note while you are at it: the board's Wi-Fi 7 and Bluetooth 5.4 need Windows 11 24H2 for their full feature set.

Buying tips: verify the exact processor on MSI's CPU support list before ordering, and match your CPU to your storage plans - if you want every M.2 slot alive and fast, Ryzen 7000/9000 is the way to go.

Buying tips

• Socket AM5: Ryzen 7000, 8000G and 9000 desktop CPUs only.
• Check MSI's CPU support list for your exact chip.
• 170 W-class parts are within the design intent; MSI states no numeric TDP limit.
• Pick Ryzen 7000/9000 to keep all four M.2 slots at full speed.

How to upgrade

Before you start

• Back up anything you care about before touching the hardware.
• Shut the computer down fully and unplug the power cable.
• Ground yourself to avoid static damage - for example touch the metal chassis before handling parts.
• Open the case. The exact disassembly differs by case and component, so follow the owner's manual for the correct steps and screw locations.
• Install the part, then close the case.
• Power up and check the BIOS/firmware reports the new memory, drive or processor correctly before relying on it.

Steps

1. RAM
   After backing up and unplugging, ground yourself and open the case. Open the double-sided latches on the DIMM slots, line the DDR5 module notch up with the slot and press it down until both latches click closed. The memory slots are what set the order and channel pairing, so check the manual for which slots to fill first. Then close the case and confirm the BIOS reports the new capacity and speed.
2. Storage
   For an M.2 drive, fit it in the slot that matches your CPU and bandwidth needs, in one of the supported lengths (2260/2280, plus 22110 on M.2_1). M.2_1 comes with a heatsink; for the other slots, check whether you need one. Use the SATA ports for 2.5-inch or 3.5-inch drives. As always: back up, power off and unplug, ground yourself, and consult the owner's manual for exact mounting hardware. Finish by checking the BIOS lists the drive.
3. CPU
   Confirm the chip is on MSI's CPU support list first. Then back up, power off and unplug, ground yourself and open the case. The processor seats in Socket AM5 (LGA-1718) - follow the owner's manual exactly for the socket mechanism and cooler fitting, as the procedure varies and the socket is easy to damage. Reconnect the 2x 8-pin CPU power, then power up and verify the BIOS detects the new processor and reports sensible temperatures.

Good to know

• Make sure you are buying for the MAX WIFI model: the non-MAX board and the 'PZ' back-connector variant are different products with different headers.
• Retail listings round up the third expansion slot inconsistently; MSI describes it as a physically x16 slot wired electrically to x4.
• Minor layout differences exist between this board and other Tomahawk variants (for example latch style), so use the manual for your exact board.

Frequently asked questions

How much RAM can the MSI MAG X870E Tomahawk Max WIFI take?

MSI states up to 256 GB total across the 4x DDR5 UDIMM slots. MSI lists the total only; 256 GB over four slots implies 64 GB modules, so confirm against MSI's QVL before buying.

Does it support ECC or registered memory?

No. The board requires non-ECC unbuffered DDR5 UDIMMs, so ECC and RDIMM modules are not supported. Workstation buyers who need ECC should look at a different platform.

Can I run four sticks at DDR5-8400 MT/s?

Unlikely. The 8400 MT/s figure is a one-stick, single-rank best case with Ryzen 9000; with all four slots populated the ceiling drops to around 6400 MT/s. Stock JEDEC speeds are 4800-5600 MT/s and AMD EXPO is supported.

Which SSDs fit in the M.2 slots?

NVMe (Key M) drives in 2280 or 2260 sizes everywhere, plus 22110 in M.2_1. SATA-protocol M.2 drives do not work - use one of the 4x SATA 6 Gb/s ports for SATA storage.

Will a drive in M.2_2 disable my USB4 ports?

It shares bandwidth with the rear USB4 40 Gbps ports: with a drive installed, both drop to x2. Forcing M.2_2 to x4 in the BIOS disables the rear USB4 Type-C ports. Also note Ryzen 8500/8300 CPUs switch M.2_2 off entirely.

Which CPUs can I install?

Socket AM5 (LGA-1718) desktop chips: Ryzen 7000, Ryzen 8000G and Ryzen 9000. MSI gives no numeric TDP limit, but the 2x 8-pin EPS connectors and VRM are designed for 170 W parts; verify your exact model on MSI's CPU support list.

Official documents and references

• MSI MAG X870E Tomahawk Max WIFI - specifications (manufacturer page)
  Official spec sheet: memory support, slot layout, storage and USB4 bandwidth notes.
• PDF MSI MAG X870E Tomahawk Max WIFI - English user manual (PDF)
  Official manual: installation steps, slot assignments, RAID support and BIOS information.
• MSI MAG X870E Tomahawk Max WIFI - product page (manufacturer)
  Overview, feature highlights and links to the CPU/memory compatibility lists.
• MSI MAG X870E Tomahawk Max WIFI - owner's manual (web copy)
  Online copy of the owner's manual, handy if you prefer reading in a browser.