One of my favorite Synology features is the DSM interface: the admin panel which you can access over the internet, giving you easy access to control your NAS, and also access your files. But sometimes this interface is really slow and laggy, making managing and accessing your Synology NAS almost impossible.
Thankfully there are often a few simple fixes to this problem, which we explore today.
If your Synology DSM interface is slow, you should firstly check your CPU and RAM usage. Also double check that you accessing it correctly, and that all your drives are healthy. Failing all this, there are a few other checks to perform too.
DSM (Admin UI): Dashboard Overview
The Synology DSM stands for DiskStation Manager (DSM) and it is an easy-to-use web interface. It’s basically a full blown operating system for your Synology NAS and its files, allowing you to open a web browser and control your NAS through it:
As long as your Synology is connected to the internet (and you have enabled the relevant settings), you can access this interface from anywhere in the world. Alternatively, you can access it over a local IP address (one starting with “192”) – for example, I access my NAS via
Hackers Beware: Don’t worry, I haven’t just provided the ‘keys’ to my NAS. That URL is known as a local URL, because it can only be accessed when you are already connected to my home network. No-one else can resolve that URL from over the internet.
I’m making that specific point because the way you access your NAS can sometimes be the cause of a slow DSM UI. There are a few other things to check, too, so let’s dive into that.
9 Reasons & Fixes For A Slow DSM Interface
Your Synology NAS is basically a computer: it has all the standard hardware (a motherboard, RAM, CPU and storage disks), meaning that it can also also be affected by normal computer ‘things’ (to use the technical term).
A running scan will slow down your NAS: meaning slow file transfer speeds, but also a laggy DSM interface. Internet issues will also contribute to slowness, as will ageing or failing hardware.
Check If RAM Or CPU Usage Is High
Some Synology NASes are quite powerful: coming with a powerful, multi-core CPU and lots of RAM. Others feel like a budget computer, with a weak CPU and only one or two gigabytes of RAM. Naturally if your NAS is fairly low-powered, any running scans or processes can slow it down.
If it’s possible to do so, you should try logging into your admin panel and seeing what the resource monitor shows you:
Pay particular attention to the first three charts (CPU, memory and network). If any of these are consistently high, it could explain the slow admin panel issues.
You can then drill into the relevant section/tab at the top, and explore the issue more. For example, if the “CPU” graph is high, click into the “CPU” section and see what scans or processes are running. It might be that your files are being re-indexed, which can slow down your NAS a lot.
Alternatively, you might not have enough RAM to accommodate all your installed applications. If this is the case, you have two options open to you:
- Consider uninstalling any applications you don’t actively use. It’s the same as any computer: redundant applications will just take up disk space and system resources, for no real benefit. Removing these programs can speed up your DSM as a result.
- Explore adding more RAM. Many of Synology’s NASes allow you to expand the RAM, which can be a great choice because they often ship with a small amount of RAM. My own DS220+ only came with 2 GB of RAM, which is fairly small – so I added an extra 4 GB. This helped my NAS feel a lot snappier.
Maybe Your NAS Is Just Too Old For DSM 7?
Another (sad) option is that your NAS is simply too old to run the latest DSM – sorry! DSM 7 was a big release for Synology back in 2021, providing a range of new features. However it came at a cost: it’s a bit more resource intensive than the older operating system version.
If you have an older NAS, one explanation for slowness is that it might just be too unpowered for the latest Synology software. This is likely to be the case if your slowness issues started after upgrading to DSM 7.
While Synology don’t allow you to officially downgrade from DSM 7, there is an unofficial method which the below YouTube video explores:
Ensure You’re Connecting The Right Way
I mentioned at the start of this article that you can access your DSM admin panel from anywhere in the world. This is possible by enabling QuickConnect, which gives you a publicly accessible URL for your admin UI:
While QuickConnect is great, accessing your NAS over the internet will always be slower than accessing it over your local network (e.g. via
http://synologynas:5000/). This is because your Synology’s network traffic have to be ‘streamed’ over the internet, when using QuickConnect.
Naturally if you are away from your home, you will have to rely on external access to your NAS (via QuickConnect). But when you are at home, you should aim to access your NAS locally. This will always be the shortest networking route from your computer to your NAS, meaning the quickest connection speeds.
Of course, other factors could be at play – including a slow computer, or dodgy Wi-Fi!
Could It Be Your Computer/Laptop?
If your computer or laptop has a slow internet connection, or it has high CPU and RAM usage, that will also appear as ‘slow’ DSM access. But in this case, it is your computer’s fault, not your NAS’ fault.
You might think that the DSM UI is ‘just’ a website (which is technically true, since you access it in your bwoser), but it is actually a fairly intricate web-based application which can slow down your computer further.
Therefore if your computer is currently running a heavy application like an anti-virus scan or a computer game, your Synology admin panel might feel quite laggy. Consider pausing or exiting these, while accessing DSM.
Equally if your computer has a dodgy Wi-Fi connection, DSM will appear slow because you are accessing it in your browser (even if it is a local connection). If you are able to connect over Ethernet, this will at least stop any Wi-Fi issues being the cause.
Check Your Drive’s Health
A NAS is only as good as its drives. If one of your drives is failing, for example, its entire performance will be degraded. While a Synology NAS does check drive health, this is often just once a month by default. So you should trigger another check manually by clicking on Storage Manager, then “HDD/SDD”. Select each drive in turn, and click “Health Info” then “S.M.A.R.T”. Here you can trigger a quick or long (“extended”) test.
You should also verify that your disk usage is below 90%. Anything above this level will start to harm performance. This is because your NAS always needs a bit of free space to perform scans, indexes and backup jobs.
Try Turning It Off And On Again?
The age old advice of “have you tried turning it off and back on again?” applies here too. A slow or laggy admin panel might just be caused by some weird, temporary issue that can’t easily be tracked by via resource monitor or device health scans.
In this case, a simple reboot can often clear out temporary data, and also restore CPU and RAM usage to low levels. Wait a few minutes after the reboot, and check the DSM again to see whether performance is better.
To trigger a reboot, click the “Person” icon in the top right and click “Restart”. Alternatively, you can press the power on/off switch on the physical device.
Tip: If this fixes the problem, I would advise to check CPU and RAM usage again after a few hours. If they are decently higher again, it might be that you have too many installed applications – all of which start to drain your NAS’ resources over time. Uninstalling any rarely used applications should help prevent a slow DSM in the future.
Reinstall Heavy Apps (Like Docker)
In addition to reviewing and uninstalling less-used applications, you might also want to consider reinstalling some heavier applications. Virtual machine applications (including Docker) can be quite resource intensive, and in rare cases they can develop data issues that result in increasingly poor performance.
Uninstalling these applications, then installing them again, can sometimes help improve performance speeds.
One downside is that you will lose any containers that you have already set-up. You might want to explore backing up any relevant data or container configuration, so you can restore them (fairly) easily.
Photo And Surveillance Stations Can Cause Slowness
Synology offer some great features like Photo Station and Surveillance Station. These are as good as the cloud-based applications (like Google Photos), but you have full control over them – no Google-owns-all-my-data cloud software for me, thanks!
While they work well, they can be fairly resource-intensive. The photo station has to process and optimize lots of pictures and thumbnails, while the surveillance station might be encoding and/or decoding a range of H.264 video codec data.
This will be fine if you have an ultra-powerful (and ultra-expensive!) Synology NAS with a dozen cores and 32 GB of RAM, but these applications might struggle if you only have 1 or 2 CPU cores and 1-2 GB of RAM.
Naturally you should see these applications use up a lot of CPU and RAM under the resource monitor, but you should still consider temporarily uninstalling these. If your DSM becomes fast to use again, that will be the cause.
The longer-term solution will then by to either install more RAM, consider upgrading your NAS, or potentially using an alternative to these useful-but-intensive packages.
Temporarily Turn Off These Settings
The Synology help page lists a bunch of settings and features that you should temporarily disable – such as their protection against Spectre and Meltdown vulnerabilities (you can do this under Control Panel -> Security -> Advanced). While you do naturally want this protection, disabling it for a few hours will at least show whether this is contributing to the DSM UI slowness you are experiencing.
Synology also suggest stopping any scheduled backups (such as via the C2 backup job), and stopping file and media indexing for a short time:
Following these steps will pause some of the most CPU and RAM intensive processes that might be slowing down your DSM admin interface. However if you still experience slowness, you probably need to contact Synology technical support in-case there is a deeper hardware issue with your device.