MSI B450 TOMAHAWK MAX II Upgrade Guide: RAM, SSD and CPU

Lifecycle and support

No longer sold new. The manufacturer hasn't published an end-of-support date.

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

RAM: four DDR4 slots, up to 128 GB

The board has four full-size desktop DDR4 slots (UDIMM) running in dual channel. There are no laptop-style SO-DIMM slots and no soldered memory, so everything is upgradeable. MSI lists a 128 GB maximum in total. MSI doesn't state a per-module limit, but Kingston's upgrade path reaches 128 GB with 32 GB modules, so 4 x 32 GB is the practical ceiling.

Official standard speeds are 1866, 2667 MHz and steps between. Faster A-XMP/XMP speeds depend on your CPU: 3rd Gen Ryzen can go up to 4133 MT/s with overclocking, while other AMD CPUs are listed up to 3466. The 4133 figure in MSI's headline spec applies only to 3rd Gen Ryzen.

Install the first module in the DIMMA2 slot and add modules in pairs for dual channel. Registered (RDIMM) and LRDIMM memory aren't listed as supported. ECC UDIMMs will work, but only in non-ECC mode. Your modules may run below their rated speed by default, so you may need to enable XMP/A-XMP or set the DRAM frequency in the BIOS.

Buying tips

• Buy DDR4 desktop DIMMs only, not SO-DIMMs and not DDR5
• Two matched modules (for example 2 x 16 GB) put less load on the memory controller than four
• MSI suggests keeping DIMM voltage below 1.35 V to protect the processor
• Don't pay extra for kits faster than 3466 MT/s unless you run a 3rd Gen Ryzen
• Filling all four slots or overclocking calls for good airflow, and stability depends on the CPU
• Usable capacity shows slightly lower than the installed amount

Storage: one M.2 slot and six SATA ports

The single M.2 slot (Key M) accepts 2242, 2260, 2280 and 22110 drives, both NVMe and SATA types. It runs at PCIe 3.0 x4 with Ryzen 1st to 3rd Gen and Ryzen APUs, or PCIe 3.0 x2 with Athlon with Radeon Vega graphics. A Gen4 NVMe drive will work, but only at Gen3 speed. MSI doesn't give a maximum drive capacity, so the limit is the drive itself.

The six SATA 6Gb/s ports take 2.5" and 3.5" drives. Two come from the CPU and four from the B450 chipset. Be aware that SATA5 and SATA6 are disabled when an M.2 drive is installed, leaving four usable SATA ports. RAID 0, 1 and 10 are supported for SATA devices only, so an NVMe drive can't join a RAID set.

Drive bays and thickness limits depend on your case, not the board. If you need more storage, the PCIe slots can take an M.2 adapter or SATA card. The board has one PCIe 3.0 x16 slot, one PCIe 2.0 x16 slot (x4 electrical) and three PCIe 2.0 x1 slots. The PCIe 2.0 x16 slot (PCI_E4) drops to x2 speed when PCI_E2 or PCI_E3 is in use.

Buying tips

• A fast Gen3 NVMe drive is enough here; paying more for Gen4 or Gen5 speed won't help
• If you plan to use more than four SATA drives, you can't also use the M.2 slot
• Check that your case has a free 2.5" or 3.5" bay before buying a SATA drive
• Use a SATA M.2 drive only if you accept that it still disables SATA5 and SATA6
• An M.2 adapter card in a PCIe slot is an option if you need more NVMe capacity

CPU: AM4 socket, Ryzen 1000 to 3000 confirmed

The board has one removable AM4 socket. MSI lists 1st, 2nd and 3rd Gen Ryzen, Ryzen with Radeon Vega graphics, 2nd Gen Ryzen with Radeon graphics and Athlon with Radeon Vega graphics. A per-model CPU list and minimum BIOS versions weren't in the documents we checked, so confirm your exact chip on MSI's CPU support page.

Ryzen 5000 support isn't confirmed. B450 boards often need a BIOS update for these chips, but MSI's documents here don't say whether this board is supported or which BIOS is required. Check MSI's support page before buying one. If a new CPU is too new for your current BIOS, the board's Flash BIOS Button lets you update from a USB key without a CPU, memory or graphics card installed. Other update methods are M-Flash and MSI Dragon Center.

MSI doesn't state a maximum CPU power (TDP) rating. It describes an extended PWM heatsink and a digital power design aimed at high-end processors. The HDMI and DVI-D video ports only work with a CPU that has integrated graphics. The main PCIe x16 slot runs at x16 with 1st to 3rd Gen Ryzen, x8 with the Vega/Radeon graphics APUs and x4 with Athlon.

Buying tips

• Check MSI's CPU support list and minimum BIOS for your exact chip before buying
• Skip Ryzen 5000 unless you've confirmed support, as it isn't confirmed here
• Buy a CPU with integrated graphics if you want to use the HDMI or DVI-D ports
• Have a proper CPU cooler and thermal paste ready
• Updating the BIOS before the swap is easiest with the Flash BIOS Button and a USB key

How to upgrade

Before you start

• Back up anything important, especially before changing drives or updating the BIOS
• Note your current BIOS version and check MSI's support page for the one your new CPU needs
• Have the owner's manual to hand for exact component positions and connector layouts
• Work on a clean, flat surface and keep screws and parts organised
• Changing the processor can reset BIOS settings to defaults, so note any settings you want to keep

Steps

1. Back up and prepare
   Back up your data and, for a CPU upgrade, update the BIOS first if your new chip needs it. The Flash BIOS Button lets you do this from a USB key without a CPU installed.
2. Power off and unplug
   Shut down the PC, switch off the power supply and unplug the power cord. MSI's manual specifically says to unplug power before installing or removing the CPU.
3. Ground yourself
   Touch bare metal on the case or use an anti-static wrist strap. Handle parts by their edges.
4. Open the case
   Remove the side panel so you can reach the board. Follow the owner's manual and your case instructions for exact disassembly.
5. Install the new part
   For RAM, fit the first module in DIMMA2 and add further modules in pairs. For an M.2 SSD, install it in the single M.2 slot, remembering that SATA5 and SATA6 will then be disabled. For a SATA drive, connect it to one of the SATA ports and to power. For a CPU, remove the cooler, swap the chip, then refit a heatsink with an even layer of thermal paste, as the manual advises.
6. Close up and reconnect
   Refit the side panel, plug the power cord back in and switch the power supply on.
7. Check the BIOS
   Start the PC and enter the BIOS. Confirm it shows the correct RAM capacity, drive or CPU. Enable XMP/A-XMP for faster memory if you want it, and reapply any settings that were reset.

Good to know

• MSI doesn't state a maximum RAM size per module; 32 GB per slot is inferred from Kingston's upgrade path
• The 4133 MT/s speed is overclocked and applies only to 3rd Gen Ryzen; other CPUs are listed up to 3466
• Ryzen 5000 support and minimum BIOS versions aren't confirmed here, so check MSI's CPU support page
• MSI doesn't publish a maximum CPU power (TDP) limit that we could find
• Case drive bays and thickness limits depend on your case, not the board
• ECC memory works only in non-ECC mode

Frequently asked questions

How much RAM can the MSI B450 TOMAHAWK MAX II take?

Up to 128 GB across four DDR4 UDIMM slots. MSI doesn't state a per-module limit, but 4 x 32 GB is the practical maximum based on Kingston's upgrade path.

What RAM speed does the B450 TOMAHAWK MAX II support?

Standard speeds run from 1866 to 2667 MHz. With A-XMP overclocking, 3rd Gen Ryzen can reach 4133 MT/s, while other AMD CPUs are listed up to 3466.

Does the B450 TOMAHAWK MAX II support NVMe SSDs?

Yes. The one M.2 slot takes NVMe and SATA drives in 2242, 2260, 2280 and 22110 lengths at PCIe 3.0 x4. Gen4 drives work but only at Gen3 speed.

Why are my SATA ports not working after installing an M.2 drive?

Installing a drive in the M.2 slot disables SATA5 and SATA6, which leaves four usable SATA ports.

Does the B450 TOMAHAWK MAX II support Ryzen 5000?

It isn't confirmed. MSI lists 1st, 2nd and 3rd Gen Ryzen, Ryzen APUs and Athlon. Check MSI's CPU support page and the minimum BIOS version before buying a Ryzen 5000 chip.

Can I update the BIOS without a CPU installed?

Yes. The board has a Flash BIOS Button that lets you update from a USB key without a CPU, memory or graphics card installed.

Official documents and references

• PDF MSI B450 TOMAHAWK MAX II datasheet
  Official specs, supported CPUs and Flash BIOS Button
• PDF MSI MS-7C02 owner's manual (v3.1)
  Memory, M.2 and SATA details and slot rules
• PDF MSI MS-7C02 user guide (v3.1, English)
  CPU installation, BIOS update and PCIe lane details
• MSI B450 TOMAHAWK MAX II product page
  Official overview and support links
• Kingston memory finder for this board
  Compatible RAM kits up to 128 GB