TerraMaster NAS memory is easy to choose and, on some models, takes real care to install. The module depends on the model: SODIMM in the F-series desktops and most T and U towers, full-size UDIMM in the older U-series rackmounts, and ECC UDIMM in the U-725 rackmounts. How you reach the slot also changes from model to model, from a side cover held by two screws to a full teardown. This guide covers which memory each TerraMaster takes, the install steps, and what to do if the NAS does not start.
Which memory does your TerraMaster take?
Match your exact model, printed on the label on the unit, to the table. Every model links to its NEMIX listing. The suffix matters: an F4-424, F4-424 Pro and F4-424 Max are different machines, and the F4-424 Max has two memory slots where the F4-424 has one.
| Module type | Speed | Largest memory | TerraMaster models |
|---|---|---|---|
| DDR5 SODIMM, non-ECC, 1 slot | DDR5-4800 | 32GB | F2-424, F4-424, F6-424, F8 SSD, F4 SSD, F4-424 Pro, F8 SSD Plus, F2-425 Plus, F4-425 Plus, F4-425 Pro |
| DDR5 SODIMM, non-ECC, 2 slots | DDR5-4800 | 64GB | F4-424 Max, F6-424 Max, U4-500, U8-500 Plus, U12-500 Plus, T9-500 Pro, T12-500 Pro, F6-425 Pro (DDR5-5600 platform) |
| DDR4 SODIMM, non-ECC | DDR4-3200 | Varies by model | F2-223, F4-223, F2-423, F4-423, T6-423, T9-423, T12-423, T9-450, T12-450, U4-423, U8-423, U12-423, U8-450 |
| DDR4 SODIMM, non-ECC, 1 slot | DDR4-3200 | 16GB | F2-425, F4-425 |
| DDR4 UDIMM, non-ECC (rackmount) | DDR4-3200 | Varies by model | U8-322-9100, U12-322-9100, U16-322-9100, U8-522-9400, U8-722-2224, U12-722-2224, U16-722-2224, U24-722-2224 |
| DDR4 UDIMM, ECC, 8 slots (rackmount) | DDR4-3200 | Varies by model | U8-725, U12-725, U12-725 Plus, U16-725 Plus |
| DDR3L SODIMM, non-ECC (older F-series) | DDR3L-1600 | 4GB per TerraMaster module | F2-221, F4-421, F5-221, F2-422, F4-422 |
DDR3L, DDR4 and DDR5 modules are keyed differently and do not fit each other's slots, and SODIMM and UDIMM are different sizes. Some models have memory with no slot at all, for example the F4-212, so check your model's specification before you buy. The TerraMaster NAS memory guide covers every model in more detail, and you can search by TerraMaster part number (A-SRAMD5-8G, A-SRAMD4-16G, A-URAMD4-16G and others) in the TerraMaster part number collection.
Before you start
- Check TerraMaster's guidance for your model. TerraMaster's RAM compatibility page lists its own modules by model, and its support advises using the memory module it provides, because other memory may stop the system from booting properly. NEMIX RAM modules are researched, matched, and compatibility-tested by NEMIX RAM and are backed by a lifetime warranty, and each listing is built to the module type and speed TerraMaster specifies for the model. If you want TerraMaster's own part, the listings above are cross-referenced to its part numbers.
- Keep the original module. Store it in an anti-static bag. If the NAS does not start with the new memory, putting the original back confirms the unit is healthy.
- Match the module to the slot count. On one-slot models the new module replaces the factory module. On two-slot models, fill both slots with modules of the same capacity and speed. Do not mix ECC and non-ECC.
- Back up your data and have a small Phillips screwdriver and a clear, soft work surface.
- Power the NAS down completely. Shut it down from TOS, wait until it is off, and unplug the power cord and every other cable before you open it.
How to install memory in a TerraMaster NAS
Step 1: Note the current memory
Sign in to TOS as an administrator and open the system information page. Write down the memory total. You will check the same page after the upgrade.
Step 2: Shut down and unplug
Shut the NAS down from TOS, wait until the power light goes out, then unplug the power cord and the network and USB cables. Do not change memory with the power on.
Step 3: Open the unit
This is the step that differs by model. Published teardowns show these layouts:
- Side cover. On the F4-424 Max, two screws on the back hold the side cover. Remove them, slide the cover forward and lift it off to find the SODIMM slots beside the M.2 slots.
- Aluminum body. On the F2-423, take out the drive trays, loosen the four screws at the back and pull the aluminum body off to expose the board. The SODIMM slots are on the board.
- Full teardown. Some models, including reviewed units of the F4-423, have no service door for the memory, and reaching it means dismantling the machine. Older F-series units such as the F2-221 need the drive trays out, the rear panel off and the board tray slid out, with the slot on the underside of the board.
Towers and rackmounts open differently again. Use the Quick Installation Guide for your model from TerraMaster, or send us your model and we will tell you what we know before you open it. If your model needs a full teardown, take photos as you go so you can reassemble it.
Step 4: Release the old module if replacing
For SODIMM, push the clips on both sides outward and the module pops up at an angle. Lift it out by its edges. For a full-size UDIMM, open the latches at both ends of the slot and lift the module straight out. Do not touch the gold contacts.
Step 5: Seat the new module
Line up the notch in the module with the notch in the slot. For SODIMM, insert the module at an angle and press it down until the clips click. For UDIMM, press both ends straight down until the latches lock. On two-slot models, fill the first slot before the second. The module should seat without force. If it resists, check the orientation and the memory type.
Step 6: Reassemble and power on
Refit the cover or body and every screw, slide the drive trays back into their original bays, reconnect the cables and press the power button.
Step 7: Confirm the new total in TOS
Sign in to TOS and open the system information page again. The memory total should show the new capacity. Leave the NAS under your normal workload for a while and check that it stays stable.
If the NAS does not start or shows less memory
- Shut down, unplug the power cord and open the unit again.
- Reseat each module until it is fully seated.
- Check the memory type: DDR3L, DDR4 or DDR5, SODIMM or UDIMM, and ECC only on the U-725 models.
- Try one module at a time. If a single module works and the pair does not, the pair may not match.
- If the unit powers on but TOS does not load, remove the new module and start with the original. TerraMaster support notes that memory it has not designated can stop the system booting, so tell us your model and we will help with the right module.
How much memory should you install?
File sharing and backup run well on the factory memory. Docker containers, virtual machines, Plex or Jellyfin, surveillance and SSD caching all benefit from more. The one-slot DDR5 models take up to 32GB in a single module, the two-slot DDR5 models up to 64GB, and the F2-425 and F4-425 up to 16GB. Do not exceed the maximum TerraMaster specifies for your model.
Find your memory
- TerraMaster NAS memory upgrades by model, every TerraMaster listing.
- The TerraMaster memory hub page and the TerraMaster memory guide.
- By type: DDR5 non-ECC SODIMM, DDR4 non-ECC SODIMM and DDR4 ECC UDIMM.
- Other brands: NAS memory by brand.
Buying for several NAS
NEMIX RAM is a US-based memory specialist, in business since 1993. Every module is researched, matched, and compatibility-tested by NEMIX RAM, is JEDEC-compliant, and is backed by a lifetime warranty. Offices, schools and integrators that run several TerraMaster units can standardize on one kit per model. Purchase orders, net terms and volume pricing are available. Request a quote with your NAS models and quantities, or contact our sales team.
NEMIX RAM is an independent memory supplier and is not affiliated with TerraMaster. TerraMaster and TOS are trademarks of their respective owners, used only to identify compatible systems. Steps are summarized from published teardowns and TerraMaster support statements; follow the instructions for your exact model.