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Docker, Memory Recommendations and Limitations

Hey so this is a new page that covers some basics that I get questions about fairly often and applies to most guides.

Container Manager or Docker?

The version of Diskstation Manager (DSM) you have installed on your Synology will define which Package for Docker itself is available to you.

Each of my guides has the appropriate icon on its featured image, so you know if you are following the correct one for your NAS.

For DSM versions 7.1 and below the package will be called Docker and have this icon – It can be installed via Package Center.

Container Manager is the new UI for Docker on DSM7.2 and above. It received a number of improvements over the previous Docker package including the ability to use Docker Compose from the UI. It can be installed via Package Center.

Memory Limitations and Performance Issues

Synology generally includes enough memory out of the box to get basic DSM features running and NAS file serving duties. For example the 220+ and 224+ come with 2GB of memory.

Once you start moving into ‘server’ duties with additional containers and packages you will hit memory limits very quickly. Even if DSM is showing X% of free memory it will begin using swap on disk which is extremely slow. Resulting in containers being sluggish, Plex or Jellyfin loading art at a snails pace and containers becoming unresponsive and causing intermittent connection issues between things such as Radarr and qBittorrent.

I would recommend upgrading to a minimum of 8GB of total RAM which will give you overall performance improvements. If you can afford to add more it will all be used as Linux also uses it for file caching.

Recommended Memory from our Discord Users

This list below is gathered directly from our Discord group and only added if someone is actively using that memory so no speculation around if it works.

Ensure you use the exact model number and not a variant, this list is updated as new submissions come in. (Last Update 10th March 2024)

24 Series

Model NoDSM Version TestedManufacturerModule Used
224+DSM 7.2.1Timetec1x16GB
224+DSM 7.2.1Timetec 1x16GB

23 Series

Model NoDSM Version TestedManufacturerModule Used
923+DSM 7.2Kingston1x16GB
423+DSM 7.2.1Crucial (Micron)1x8GB
423+DSM 7.2.1Timetek1x8GB
423+DSM 7.2.1Crucial (Micron)1x8GB
423+DSM 7.2.1Crucial (Micron)1x16GB
723+DSM 7.2.1Crucial (Micron)2x16GB

21 Series

Model NoDSM Version TestedManufacturerModule Used
1821+7.2Kingston 2x16GB
1821+7.2Crucial (Micron)2x16GB Kit
1821+7.2.1-69057 Update 4Team Group1x16GB
1821+7.2.1-69057 Update 4Timetec1x16GB 79TT26EUS2R8-16G

20 Series

Model NoDSM Version TestedManufacturerModule Used
1520+DSM 7.2Crucial (Micron)1x16GB Kit
1520+DSM 7.2.1Samsung1x16GB Kit
920+DSM 7.2Crucial1x8GB Kit
920+DSM 7.2Crucial1x16GB Kit
920+DSM 7.2Crucial1x16GB Kit
(Mixed results try other sticks)
920+DSM 7.2Crucial1x16GB
920+DSM 7.2Samsung1x16GB
720+DSM 7.2.1Kingston1x16GB
220+DSM 7.2Kingston1x16GB
220+DSM 7.2Crucial (Micron)1x8GB
220+DSM 7.2Crucial (Micron)1x16GB

18 Series

Model NoDSM Version TestedManufacturerModule Used
1019+DSM 7.2.1Crucial (Micron)2x8GB CT102464BF160B.C16

18 Series

Model NoDSM Version TestedManufacturerModule Used
918+DSM 7.2Samsung1x4GB
918+DSM 7.2SK Hynix1x4GB
718+DSM 7.2Crucial (Micron)2x8GB
218+DSM 7.2.1Crucial (Micron)1x8GB

16 Series

Model NoDSM Version TestedManufacturerModule Used
416playDSM 7.2.1Crucial (Micron)1x8GB

15 Series

Model NoDSM Version TestedManufacturerModule Used
1815+DSM 7.1.1Crucial (Micron)2x8GB
1515+DSM 6.xCrucial (Micron)2x8GB

12 Series

Model NoDSM Version TestedManufacturerModule Used
412+DSM 6.xKingston1x4GB


  1. boasist boasist

    Can confirm that the CT16G4SFRA32A does NOT work in a 920+ running DSM 7.2.1-69057 Update 1. Blinking blue light and no official boot.

    I have a CT16G4SFRA266 on it’s way and will hope for better results.

    • Dr_Frankenstein Dr_Frankenstein

      Thanks – I wonder why it’s not working for you as had one person with a confirmed working stick – I will pop a warning/remove it from the list if It’s going to be iffy..

      • boasist boasist

        I didn’t research it much after a couple of failed boots.

        Today the CT16G4SFRA266 arrived and that came right up on the first boot as usual. DSM reports 20gb and all is stable for now. No warnings or errors to report.

        • Dr_Frankenstein Dr_Frankenstein

          Perfect – I will keep an eye out for anyone else with issues, maybe a faulty stick? Good thing is there are a few to choose from, that extra will really make things snappy

  2. StangD StangD

    Hi there, I used your guide years ago and it’s been working fantastic, thank you! I am currently running DSM 7.1.1-xxxx and would like to update my DSM to the latest release. Is there a documented process to update and restore functionality to all of this or will it “just work”? I’m sure that’s a loaded question however having difficulty finding info about it. Thank you very much in advance

  3. Brian Brian

    So is there real risk using unapproved RAM in a Synology NAS? I have a 923+ and there is real difference in price between what you are recommending and what is approved by Synology. I am interested in your thoughts.

    • Dr_Frankenstein Dr_Frankenstein

      The only ‘risk’ is that Synology deny support requests while the RAM is installed. Hardware wise there are none.

  4. Squishy Squishy

    I have DS 224+ but added 4gb as I was told it could only do 6gb max and synology states this too

    Im going to buy the 16gb stick and see, I have seen others put more ram in than 6gb and it work, I just wonder even if it shows 18gb, can it actually use the 18gb or is it just visual?

    I am unsure due to conflicting reports, I will buy some anyway and see how it goes.

    • Dr_Frankenstein Dr_Frankenstein

      Heard many conflicting bits of info as well, it will 100% use all 16GB for file caching so that will provide a ton of benefit. Apps wise I have read that it’s the 6GB, however that just feels kind of weird that they could limit apps..which ever way you will get a nice speed boost for a relatively inexpensive upgrade.

    • I can confirm the upgrade of a additional 16GB works.

      I have added a Crucial 16GB 2400MHz DDR4 SODIMM (1x16GB) (CT16G4SFD824A)

      I do see it’s upgraded to 18GB now. And i have updated /etc.defaults/synoinfo.conf to 18GB.

      All seems to work just fine.

      • will will

        can you elaborate on updating synoinfo.conf? i installed the recommended ram listed above in my 923+ and resource monitor is not detecting the new module. wondering if i got a defective stick

        • Dr_Frankenstein Dr_Frankenstein

          You shouldn’t need to update anything other than installing the module. Make sure you have seated the stick fully.

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