MSI MAG B650 TOMAHAWK 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: 4 DDR5 slots, up to 256 GB

The board has four full-size DDR5 DIMM slots (not laptop SO-DIMMs) running in dual-channel. It takes non-ECC unbuffered memory only, so registered or buffered modules won't work. AMD EXPO profiles are supported. Standard speed is 4800 MT/s, and modules may run below their rated speed until you set the DRAM frequency in the BIOS.

MSI's current manual and specification page give 256 GB as the maximum. Older documents say 192 GB, and one retailer listing says 128 GB. The lower figures likely date from the board's launch, so we go with MSI's current 256 GB. MSI doesn't state a per-module maximum. 256 GB across four slots implies 64 GB modules, but that is unconfirmed.

Speed depends on how many slots you fill. The top overclock of 7600+ MT/s needs one single-rank module per channel. Two modules per channel drops that to 6400+ MT/s for single-rank or 5400+ MT/s for dual-rank. One module per channel with dual-rank modules is listed at 6400+ MT/s. One retailer datasheet lists a lower 6400+ MT/s maximum, which probably reflects an earlier spec.

Buying tips

• Buy a matched kit, with the same type, number and density of modules, for stable dual-channel running.
• If you only need two modules, fit them in DIMMA2 first, as the manual instructs, and the matching slot for the second.
• Choose EXPO-rated kits for easy setup, then enable the profile in the BIOS.
• Filling all four slots or overclocking? MSI recommends better memory cooling.
• Single-rank modules keep higher speeds possible with four slots filled.

Storage: three M.2 NVMe slots and six SATA ports

M2_1 is fed by the CPU at PCIe 4.0 x4 and takes 2280 or 22110 drives. M2_2 (CPU) and M2_3 (chipset) are also PCIe 4.0 x4 and take 2260 or 2280 drives. MSI's documents don't say whether M.2 SATA drives work in these slots, so check the manual before buying one. The Wi-Fi card uses a separate M.2 Key-E slot that is not for storage.

Two things reduce what you can use. M2_3 shares bandwidth with the PCI_E2 slot, so if both are in use each runs at x2. M2_2 is unavailable if you fit a Ryzen 8500 or 8300 series processor.

There are also six SATA 6 Gb/s ports for 2.5-inch or 3.5-inch drives. Four come from the B650 chipset and two (SATA_A1_A2) from an ASM1061 controller. MSI lists RAID 0, 1 and 10 for SATA drives and RAID 0 and 1 for NVMe drives. An older manual copy also lists RAID 10 for NVMe, so don't count on that. The ASM1061 ports don't support RAID. MSI gives no per-drive or total capacity limit. Drive bays and thickness limits depend on your case, and you will need SATA cables.

Buying tips

• For the fastest drive, use M2_1 and choose a PCIe 4.0 NVMe SSD in 2280 or 22110 length.
• Stick to 2280 drives to be sure of fitting any of the three slots.
• Avoid using M2_3 and PCI_E2 together if you want full speed on both.
• Plan RAID arrays on the chipset SATA ports, not SATA_A1_A2.
• Check your case has free 2.5-inch or 3.5-inch bays before buying SATA drives.

CPU: AM5 for Ryzen 7000, 8000G and 9000

The CPU is a standard removable part in a single AM5 socket. MSI's current documents list Ryzen 7000, 8000 and 9000 desktop processors. MSI's own CPU support statements have grown over time: the original manual lists only Ryzen 7000, and older documents add the 8000 series. That means a board with an older BIOS may not boot a newer chip.

Before buying a Ryzen 8000 or 9000 CPU, look up the minimum BIOS for your exact processor on MSI's CPU support page. If your board has an older BIOS, MSI's Flash BIOS button can update it with no CPU or memory installed. M-FLASH and MSI Center Live Update also work, but only with a CPU that already boots.

Ryzen 8000G processors change the PCIe lanes the CPU provides. The main x16 slot runs at x8 on the 8700, 8600 and 8400 and at x4 on the 8500 and 8300. M2_2 is unavailable on the 8500 and 8300. MSI's documents don't state a maximum CPU power rating for this board, so rely on MSI's CPU support page for each chip. The board offers user-selectable power profiles such as a 65W ECO mode, which are limits you can choose rather than a hardware ceiling.

Buying tips

• Check the minimum BIOS version for your exact CPU on MSI's support page before buying.
• If the board might have an old BIOS, plan to update it first, using the Flash BIOS button if needed.
• Avoid Ryzen 8500G or 8300G if you want to use M2_2 or a full-speed graphics slot.
• Budget for a compatible AM5 cooler, and keep spare thermal paste to hand.

How to upgrade

Before you start

• Check the CPU support page on MSI's site for the minimum BIOS version of any new processor.
• Note your current BIOS version in the BIOS screen so you know whether an update is needed.
• Back up any important data, especially before changing or cloning drives.
• Have the owner's manual to hand for exact slot positions and screw locations.
• Check your case has room for any extra SATA drives, and that your cooler fits AM5.

Steps

1. Back up and update if needed
   Back up your files. If you are installing a Ryzen 8000 or 9000 CPU, update the BIOS first using MSI's Flash BIOS button (a USB drive with the BIOS file renamed MSI.ROM, power connected to CPU_PWR1 and ATX_PWR1) or M-FLASH from a working system.
2. Power off and unplug
   Shut the PC down, switch off the power supply and unplug the power cable and all other cables.
3. Ground yourself
   Touch a bare metal part of the case, or use an anti-static wrist strap, before handling parts. Hold components by their edges.
4. Open the case
   Remove the side panel. Follow your case's manual and the motherboard's owner's manual for exact disassembly.
5. Install RAM
   Release the clips on the slots, line up the notch on the module and press down evenly until the clips close. With two modules, use DIMMA2 first and fit modules of the same type and density.
6. Install an M.2 or SATA drive
   Fit an M.2 SSD into the slot that suits its length and your lane needs, and secure it as shown in the manual. For a SATA drive, mount it in a bay and connect a SATA data cable to a port and the power cable from the power supply.
7. Install a CPU
   Lift the socket lever, align the CPU's two notches and its golden triangle (pin 1) with the socket, and lower it in place. Keep the socket's protective cap, because MSI will only handle RMA requests if the board comes back with the cap on the socket. Then fit the cooler with thermal paste, making sure it is seated tightly.
8. Close up and reconnect
   Refit the side panel, reconnect the cables and power on.
9. Check the BIOS
   Enter the BIOS and confirm it shows the new CPU, memory capacity and drives. Enable the EXPO profile or set the DRAM frequency so your RAM runs at its rated speed.

Good to know

• MSI's documents don't state a per-module RAM maximum; 64 GB modules are implied by the 256 GB total but unconfirmed.
• Maximum memory is stated differently in older documents (192 GB) and one retailer listing (128 GB). MSI's current figure is 256 GB.
• Documents disagree on the top memory speed: MSI lists 7600+ MT/s as an overclock with one single-rank module per channel, while one datasheet lists 6400+ MT/s.
• Documents disagree on M.2 RAID: the current manual says RAID 0 and 1, and an older copy says RAID 0, 1 and 10.
• MSI's documents don't say whether M.2 SATA drives work in the M.2 slots.
• The minimum BIOS version for each CPU, and a maximum CPU power rating, are not given in the documents we reviewed. Check MSI's CPU support page.
• One retailer listing describes the main x16 slot as PCIe Gen 3, which contradicts MSI's PCIe 4.0 specifications; trust MSI.

Frequently asked questions

How much RAM can the MSI MAG B650 TOMAHAWK WIFI take?

MSI's current manual and specification page say 256 GB across four DDR5 slots. Older documents say 192 GB and one retailer lists 128 GB, which probably reflect the original launch limit. MSI doesn't state a per-module maximum, so 64 GB modules are implied but unconfirmed.

Does the B650 Tomahawk WIFI support EXPO and ECC memory?

AMD EXPO profiles are supported. ECC and registered memory are not: the board takes non-ECC unbuffered DDR5 only.

Does it support Ryzen 9000 CPUs?

Yes, MSI's current documents list Ryzen 9000, 8000 and 7000. Older documents don't mention Ryzen 9000, so an older BIOS may not boot one. Check MSI's CPU support page for the minimum BIOS, and use the Flash BIOS button to update if needed.

How many SSDs can I install?

Three M.2 NVMe SSDs (PCIe 4.0 x4 each) plus up to six SATA drives. M2_3 and PCI_E2 share bandwidth, and M2_2 is unavailable with Ryzen 8500 or 8300 CPUs.

Can I use an M.2 SATA SSD?

MSI's documents don't say, so check the owner's manual before buying one. NVMe drives are the safe choice for the M.2 slots, and SATA drives can use the six SATA ports.

Can I update the BIOS without a CPU installed?

Yes. The Flash BIOS button can update the BIOS with no CPU or memory fitted. Put the BIOS file, renamed MSI.ROM, on a USB drive, connect CPU_PWR1 and ATX_PWR1, plug the drive into the Flash BIOS port and press the button.

Official documents and references

• PDF MSI MAG B650 TOMAHAWK WIFI manual (PDF)
  Current manual with RAM, M.2 and installation notes
• MSI MAG B650 TOMAHAWK WIFI specifications
  Official slot, memory speed and CPU support details
• MSI MAG B650 TOMAHAWK WIFI product page
  Overview and BIOS feature notes
• PDF MSI MAG B650 TOMAHAWK WIFI manual (older copy, PDF)
  Flash BIOS button steps; some limits are out of date
• MSI MAG B650 TOMAHAWK WIFI manual on ManualsLib
  CPU and cooler installation guidance
• PDF MSI MAG B650 TOMAHAWK WIFI datasheet (PDF)
  Summary specs including Ryzen 9000 support