ASUSTOR NAS memory spans three generations: DDR3 and DDR3L in the original AS-series, DDR4 SODIMM in the Nimbustor, Lockerstor and Flashstor lines, and DDR5 in the Gen3 and Pro Gen2 systems. This guide matches your ASUSTOR model to its module. The NEMIX RAM catalog lists 63 ASUSTOR listings covering 57 models, shown below by module type with a link to each. For part numbers and series pages, see the ASUSTOR NAS memory hub and the ASUSTOR NAS memory collection.
Step 1: Find your exact ASUSTOR model and what is installed
ASUSTOR model names have a marketing name and a model number, for example LOCKERSTOR 4 Gen2 (AS6704T). The model number on the label on the unit is the one to match, and listings in this guide show both. The generation matters: a LOCKERSTOR 4 (AS6604T), LOCKERSTOR 4 Gen2 (AS6704T) and LOCKERSTOR 4 Gen3 (AS6804T) take different memory. ADM, ASUSTOR's operating system, shows installed memory on its system information page.
Step 2: Match the module type to your ASUSTOR series
| ASUSTOR series | Module type | Examples |
|---|---|---|
| Original AS5 and AS6 series, AS7 desktop | DDR3 or DDR3L SODIMM, non-ECC | AS5004T, AS6204T, AS6210T, AS7008T |
| AS7 rackmount | DDR3 UDIMM, ECC or non-ECC | AS7009RD, AS7009RDX, AS7012RDX |
| Nimbustor, Lockerstor and Flashstor | DDR4 SODIMM, non-ECC | Nimbustor 2 and 4, Lockerstor 4 Gen2, Flashstor 6 and 12 Pro |
| Lockerstor Pro | DDR4 ECC SODIMM or UDIMM | Lockerstor 10 Pro, 12R Pro, 16R Pro |
| Gen3 and Flashstor Gen2 | DDR5 SODIMM, ECC or non-ECC | Lockerstor 4, 6, 8 and 10 Gen3; Flashstor 6 and 12 Pro Gen2 |
| Rackmount Pro Gen2 | DDR5 ECC UDIMM | Lockerstor 12R, 16R and 24R Pro Gen2 |
DDR3, DDR4 and DDR5 modules are keyed differently and do not fit each other's slots. SODIMM and UDIMM are different sizes.
Step 3: Decide whether you need ECC
ECC memory detects and corrects single-bit errors, which matters most for business data, virtual machines and storage that stays on for years. The ASUSTOR Pro and rackmount lines have ECC listings. For the DDR5 Gen3 and Flashstor Gen2 SODIMM models, NEMIX RAM lists both an ECC and a non-ECC option; check the ASUSTOR specification for your model and any module already installed, and do not mix ECC with non-ECC in one NAS.
Step 4: Find your model below
Every model links to its listing, and where a model has both an ECC and a non-ECC option both are linked. The last column shows the largest kit NEMIX RAM lists for the models in that row; the ASUSTOR specification for your model sets the supported maximum.
DDR5 SODIMM (Gen3 and Flashstor Gen2)
| Speed | Models | Largest kit listed |
|---|---|---|
| DDR5-4800 | FLASHSTOR 6 Gen2 (FS6806X) (ECC, non-ECC), FLASHSTOR 12 Pro Gen2 (FS6812X) (ECC, non-ECC), LOCKERSTOR 4 Gen3 (AS6804T) (ECC, non-ECC), LOCKERSTOR 6 Gen3 (AS6806T) (ECC, non-ECC), LOCKERSTOR 8 Gen3 (AS6808T) (ECC, non-ECC), LOCKERSTOR 10 Gen3 (AS6810T) (ECC, non-ECC) | 96GB |
DDR5 ECC UDIMM (rackmount Pro Gen2)
| Speed | Models | Largest kit listed |
|---|---|---|
| DDR5-4800 | LOCKERSTOR 12R Pro Gen2 (AS7212RDX), LOCKERSTOR 16R Pro Gen2 (AS7216RDX), LOCKERSTOR 24R Pro Gen2 (AS7224RDX) | 192GB |
DDR4 SODIMM
DDR4 ECC UDIMM (Lockerstor Pro rackmount)
| Speed | Models | Largest kit listed |
|---|---|---|
| DDR4-2666 | LOCKERSTOR 12R Pro (AS7112RDX), LOCKERSTOR 16R Pro (AS7116RDX) | 128GB |
DDR3 and DDR3L (original AS-series)
| Speed | Models | Largest kit listed |
|---|---|---|
| DDR3-1600 | AS7004T, AS7008T, AS7009RD, AS7009RDX, AS7010T, AS7012RD, AS7012RDX | 16GB to 32GB |
| DDR3-1866 | AS5002T, AS5004T, AS5008T, AS5010T, AS5102T, AS5104T, AS5108T, AS5110T, AS6102T, AS6104T, AS6202T, AS6204RD, AS6204RS, AS6204T, AS6208T, AS6210T, AS6212RD, AS6302T, AS6404T | 8GB |
Step 5: Choose capacity
A NAS uses RAM to cache frequently read data and to run apps. File serving alone needs little. Virtual machines, containers, Plex or other media servers, surveillance recording and large snapshot sets all use more. The Flashstor models are all-NVMe systems where fast storage can outrun a small memory configuration, so memory headroom is worth planning for. Start from what is installed, add the workloads you plan to run, and use the largest kit your ASUSTOR specification supports if you expect to grow. Fill slots with matched modules.
Step 6: Installing and checking
Shut the NAS down and unplug it, ground yourself, open the memory compartment and seat the module firmly until it clicks. After the first boot, confirm the full capacity in ADM. ASUSTOR's own AS-GD part numbers are listed in the ASUSTOR part number cross-reference.
Other brands are on the NAS memory by brand page, and the NAS memory guide covers choices that apply to every brand.
Buying NAS memory for an office, a school or a fleet
Researched, matched, and compatibility-tested by NEMIX RAM, a US-based server memory specialist since 1993, and backed by a lifetime warranty. Purchase orders, net terms and volume pricing are available for businesses, schools, government agencies, integrators and resellers. Request a quote with your NAS models and quantities, or contact our sales team. Public-sector buyers can start from the education and government page.
Don't see your ASUSTOR?
Send us the model name or the part number on an installed module and we will confirm a compatible module before you order.
NEMIX RAM is an independent memory supplier and is not affiliated with the NAS makers named here. ASUSTOR, ADM, Lockerstor, Nimbustor and Flashstor are trademarks of their respective owners, used only to identify compatible systems.