Lenovo ThinkCentre M90t Gen 6 Tower Upgrade Guide: RAM and Storage

Lifecycle and support

A current model: sold new and supported. Support is planned until Nov. 29, 2031.

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

Memory (RAM): four DDR5 slots, 128 GB tested maximum

The M90t Gen 6 has four full-size DDR5 UDIMM slots (not laptop-style SO-DIMMs) and supports dual-channel operation. Lenovo lists 128 GB as the maximum total. That is a tested limit, so larger modules may work but are not validated. The maximum size per module isn't stated; four slots at 128 GB implies 32 GB modules, but that is our reading rather than a confirmed figure.

Only non-ECC, unbuffered memory is supported. ECC and registered modules (RDIMMs) won't work. The modules are rated DDR5-5600, but depending on your processor's memory support they may run at DDR5-4400 or DDR5-4800 instead. Buying faster memory than your CPU supports won't make it run faster.

Some configurations ship with two 16 GB DDR5-5600 modules, which presumably leaves two slots free. Lenovo's documents don't say so explicitly, so open the case and look before you buy.

Buying tips

• Buy full-size desktop DDR5 UDIMM, non-ECC and unbuffered. Not SO-DIMM, not ECC, not registered.
• Matching a kit to your existing modules is the simplest route to stable dual-channel memory.
• Don't pay extra for speed above what your CPU supports: 4400 or 4800 MT/s is possible even with DDR5-5600 modules.
• Staying at or under 128 GB total keeps you inside Lenovo's tested range.

Storage: M.2 NVMe, 3.5-inch and optional 2.5-inch bays

There are three M.2 slots for SSDs, listed as M.2 2280 NVMe, PCIe 4.0 x4 or 5.0 x4. A fourth M.2 slot is for WLAN only. Lenovo lists up to 2 TB per SSD as a tested limit. Which slot runs at PCIe 5.0 and which at 4.0 isn't stated. SATA M.2 drives and other lengths (2242, 2260, 22110) aren't mentioned, so stick with 2280 NVMe. One variant's spec sheet (12YS000XGE) describes the three slots as being for an SSD or a discrete NPU; other sheets say SSD only.

For bulk storage there are two 3.5-inch SATA bays (6 Gb/s, 7.2K RPM), with up to 2 TB per drive tested. Larger drives may work. The second 3.5-inch bay is optional and may not be fitted or populated on your unit. There is also an optional 2.5-inch bay intended for customer self-upgrade, with the drive sold separately. Its thickness limit and interface aren't stated (SATA is the likely interface, based on the 3.5-inch listing), and it may not be present on every configuration.

RAID 0/1/5 appears in some spec sheets but not in every copy of Lenovo's spec PDF, so confirm RAID support for your exact configuration before planning around it.

Buying tips

• For an SSD, choose M.2 2280 NVMe. A PCIe 4.0 drive is a safe match, and a 5.0 drive is listed as supported.
• Check the 2.5-inch drive thickness limit in the Hardware Maintenance Manual before buying, since it isn't published in the specs.
• Open the case to see which bays your unit actually has before buying brackets or drives.
• If you need RAID, confirm it for your SKU first.

How to upgrade

Before you start

• Find your exact model or SKU (for example the code on the label or in the BIOS) and check it against the Hardware Maintenance Manual.
• Back up important files before opening the case.
• Look at what's already installed: how many memory modules, which M.2 slots are filled, and whether the optional bays are fitted.
• Have a small screwdriver ready and a clean, static-safe workspace.
• Check for a BIOS update on Lenovo's support site if you're fitting new or high-capacity parts. Lenovo's documents don't say one is required.

Steps

1. Back up and shut down
   Save your data, then shut the PC down completely (not sleep or hibernate).
2. Unplug and discharge
   Disconnect the power cable and all other cables. Press the power button for a few seconds to drain residual power.
3. Ground yourself
   Touch bare metal on the case or wear an anti-static strap before handling parts. Hold memory modules and SSDs by their edges.
4. Open the case
   Lay the tower on its side and remove the side cover. Follow the Hardware Maintenance Manual for the exact release method and any parts that must come out to reach the slots.
5. Install the part
   For memory, seat the DDR5 module firmly in a free slot. For an M.2 SSD, fit a 2280 NVMe drive in one of the three SSD slots (not the WLAN slot). For a SATA drive, mount it in a free bay and connect its data and power cables. The manual's memory module section shows the correct procedure.
6. Close up and reconnect
   Refit the cover, reconnect the cables and power on.
7. Check it's detected
   Enter the BIOS and confirm the new memory total or drive appears. A new drive may need to be initialised and formatted in your operating system. If memory isn't detected, power off and reseat it.

Good to know

• The 128 GB memory and 2 TB drive figures are Lenovo's tested limits, not hard limits. Larger parts may work but aren't validated.
• The maximum size per memory module isn't stated.
• Which M.2 slot runs at PCIe 5.0 and which at 4.0 isn't stated.
• M.2 lengths other than 2280 and SATA M.2 drives aren't mentioned.
• The 2.5-inch bay's thickness limit and interface aren't stated, and the bay and the second 3.5-inch bay may not be fitted on your unit.
• RAID 0/1/5 appears in some spec sheets but not all, so confirm it for your configuration.
• One variant's sheet describes the three non-WLAN M.2 slots as being for an SSD or a discrete NPU; others say SSD only.
• Lenovo's documents we checked don't cover CPU upgrades. Check the Hardware Maintenance Manual and your exact SKU before buying one.

Frequently asked questions

How much RAM can the ThinkCentre M90t Gen 6 take?

Lenovo lists 128 GB across four DDR5 slots. That is a tested limit, so larger modules may work but aren't validated. The per-module maximum isn't stated.

Does the M90t Gen 6 support ECC memory?

No. It uses non-ECC, unbuffered DDR5 UDIMMs only. ECC and registered modules are not supported.

Will DDR5-5600 memory actually run at 5600 MT/s?

Not necessarily. Depending on your processor, memory may run at DDR5-4400 or DDR5-4800.

How many SSDs can I add, and what type?

There are three M.2 slots for SSDs, listed as M.2 2280 NVMe (PCIe 4.0 x4 or 5.0 x4), up to 2 TB each as a tested limit. A fourth M.2 slot is reserved for WLAN.

Can I add a 2.5-inch drive or a second hard drive?

The system supports two 3.5-inch SATA bays and an optional 2.5-inch bay, but the second 3.5-inch bay and the 2.5-inch bay may not be fitted on your configuration. Check inside your PC.

Can I upgrade the CPU?

Lenovo's documents we checked don't describe CPU upgrades or list compatible processors. Memory speed varies by processor, so different CPU models are fitted across configurations. Check the Hardware Maintenance Manual and Lenovo support for your SKU before buying a processor.

Official documents and references

• PDF Lenovo ThinkCentre M90t Gen 6 Hardware Maintenance Manual
  Step-by-step disassembly and memory module replacement
• PDF Lenovo PSREF spec sheet (PDF)
  Memory, storage and expansion slot specifications
• Lenovo PSREF product page
  Configuration details including factory memory and SSD
• PDF Lenovo ThinkCentre M90t Gen 6 User Guide
  Slot counts and general owner information
• Bechtle datasheet for a M90t Gen 6 configuration
  Drive bay list and RAID line
• PDF Datasheet for the 12YS000XGE configuration
  M.2 slot wording for the Q870 variant