The Synology DS1825+ is an 8 bay NAS with two memory slots, and it takes a specific kind of memory: DDR4 ECC SODIMM. That narrows the choice quickly, but there are still details worth getting right, such as how much memory the unit supports, which configurations fill the slots, and what Synology says about modules it did not make. This guide lists the compatible memory for the DS1825+ and how to choose a size.
The short answer
- The DS1825+ takes DDR4 ECC SODIMM. Non-ECC modules, desktop UDIMM and DDR5 are not the right type.
- It has two slots and a 32GB maximum, made up of two 16GB modules.
- It ships with one 8GB module, so the usual upgrades are 16GB or 32GB.
- Use identical modules. Synology says multi-module configurations must use identical modules with the same model number.
- Synology recommends its own modules and states that it will not provide complete product warranty or technical support when other memory is used for expansion.
DS1825+ memory specifications
| DS1825+ memory | Specification |
|---|---|
| Processor | AMD Ryzen V1500B, 4 cores and 8 threads, 2.2 GHz |
| Memory type | DDR4 ECC SODIMM |
| Memory slots | 2 |
| Pre-installed memory | 8GB (1 x 8GB) |
| Maximum memory | 32GB (2 x 16GB) |
Memory configurations that fit
| Total memory | Modules | Notes |
|---|---|---|
| 8GB | 1 x 8GB | The factory configuration, with one slot free |
| 16GB | 1 x 16GB, or 2 x 8GB | A single 16GB module leaves a slot free; a 2 x 8GB kit fills both |
| 32GB | 2 x 16GB | The maximum, filling both slots |
Because Synology asks for identical modules, the cleanest way to reach 16GB or 32GB is to install a matched kit in both slots and retire the factory module, instead of pairing a new module with the original. A kit is sold as a matched pair, so both modules are the same.
Compatible modules from NEMIX RAM
NEMIX RAM lists DDR4-3200 ECC SODIMM for the DS1825+ in four options: 8GB as one module, 16GB as one module, 16GB as a 2 x 8GB kit and 32GB as a 2 x 16GB kit. Each is researched, matched and compatibility-tested by NEMIX RAM. The Synology DS1825+ memory upgrade listing has all four. If you want a module matched to the model number of Synology's own D4ES03 series, see the D4ES03-8G compatible 8GB and D4ES03-16G compatible 16GB listings.
How much memory do you need?
The 8GB the unit ships with covers file sharing and light services. Memory use rises with what you run on top of storage, such as containers, virtual machines, surveillance, or many users and large folders at once. Open Resource Monitor in DSM and look at memory use during a busy period. If it sits near the top, 16GB gives you headroom, and 32GB is the ceiling for the unit.
Warranty and support
Synology states on its DS1825+ page that it will not provide complete product warranty or technical support if non-Synology memory is used for expansion, and that it recommends Synology modules for the best compatibility. You should weigh that when you choose. NEMIX RAM modules carry a lifetime warranty from NEMIX RAM, and you can register your purchase to activate it. If the unit has a hardware issue, tell Synology support which memory you installed.
Installing the memory
Shut the unit down and disconnect power before you open it. Our guide to installing DDR4 ECC SODIMM in a Synology NAS walks through the steps, and the Synology NAS memory guide covers other models. After the unit boots, check the memory total in DSM to confirm both modules are recognized.
Memory that will not work
- Non-ECC SODIMM. Synology lists the DS1825+ with ECC memory. The related DS1825neo+ is a different model that Synology lists with non-ECC SODIMM, so check each model's page.
- DDR5 or DDR3. The unit takes DDR4.
- Desktop UDIMM or server RDIMM. These are different module types and do not fit a SODIMM slot.
The ECC vs non-ECC guide and the memory types explained guide cover the differences, and the compatible RAM guide shows the general method. Browse all DDR4 ECC SODIMM or the NAS memory page, or send us your model and we will check it.
Frequently asked questions
How much RAM can a Synology DS1825+ hold?
32GB, as two 16GB modules. The unit has two memory slots and ships with one 8GB module.
Does the DS1825+ use ECC memory?
Yes. Synology lists DDR4 ECC SODIMM for the DS1825+, so ECC SODIMM is the module type to buy.
Can I add a second module next to the factory 8GB module?
Synology says multi-module configurations must use identical modules with the same model number. A new module will not share a model number with the factory module, so the safer route is to install a matched kit in both slots.
Will third-party memory affect my Synology warranty?
Synology states it will not provide complete product warranty or technical support if non-Synology memory is used for expansion. Read Synology's page and decide before you buy, and keep the original module in case you need to put it back.
Does NEMIX RAM supply memory for the DS1825+?
Yes. We list DDR4-3200 ECC SODIMM for the DS1825+ in 8GB, 16GB and 32GB configurations, each compatibility-tested by NEMIX RAM. Send us the model if you want it confirmed.
Sources
Synology DS1825+ product page, read on October 29, 2026. Specifications and support terms change, so confirm them on Synology's current page.
Buying memory for NAS and business storage
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; register your purchase to activate it. Purchase orders, net terms and volume pricing are available for business, reseller and public-sector orders. Request a quote with your models and quantities, or contact our sales team.
NEMIX RAM is an independent memory supplier and is not affiliated with Synology or the other companies named here. Synology, DiskStation, DS1825+, DSM and D4ES03 are trademarks of their respective owners, used here only to identify sources and compatible systems.