Synology DS420+ vs QNAP TS-451D2 NAS Comparison

Comparing the Synology DS420+ vs the QNAP TS-451D2 NAS Drive

There are ALOT of different Network Attached Storage solutions out there. When it comes to choosing the right NAS for first-time buyers, a RAID 5 ready 4-Bay solution will always a solid and robust first-time purchase. In 2020 and 2021, we have seen the average standard of 4 drive (hard drive or SSD, depending on performance requirements) NAS servers rise substantially and alongside after processors and more memory (some supporting staggering 64GB), we are starting to see almost uniform NVMe SSD cache support, 10Gbe in copper and fiber and PCIe upgradability become available on the compact and modest 4-Bay system. Today I want to compare two NAS systems that are almost a year and 6 months old respectively, but BOTH are still remarkably popular examples of compact, powerful and affordable NAS solutions from Synology and QNAP. The Synology DS420+ NAS, released back in Summer 2020, is the latest generation in their home NAS series for users that want features and functionality, but not an aching pain in the wallet that more aggressive systems like the DS920+ and DS1520+ make! Meanwhile, the QNAP TS-451D2 NAS is an often compared product, released in Autumn 2020 and arriving at a similar price and hardware point, but with a greater emphasis on hardware (with several notable extras and brand-centric improvements featured). Both systems have key advantages and disadvantages, as well as definitely have a different target audience in mind. So, let’s compare the Synology DS420+ and QNAP TS-451D2 NAS to see which one deserves your data?

NASCompares Review of the Synology DS420+ NAS

NASCompares Review of the QNAP TS-451D2 NAS

What can Both of the QNAP TS-451D2 and Synology DS420+ NAS Do?

Of course, if you are going to go to the trouble of spending hundreds of pounds on a good network storage solution, whether as an alternative to cloud services like DropBox and Google Drive, or as a means of streaming all of your media, then chances are that you want to be doubling sure that it is going to be able to perform the tasks you need

  • Both units feature the Intel-based processors for a good price vs hardware balance in the Intel Celeron series
  • Both the DS420+ and TS-451D2 are built of plastic desktop compact chassis, thereby reducing power consumption, noise and heat generated
  • Both can Stream and Transcode on the fly (so, live) 1080p HD or 4K media, with superior performance natively and mid-range performance in Plex, though if you want a top-end Plex Media Server for 2020, you need to look at an i3, i5 or i7 Processor NAS
  • Both the Synology DS420++ and TS-451D2 NAS support AI-supported photo and ‘thing’ recognition supported to a very high degree from the free branded software included, in the form of QNAP QuMagie and Synology Moments (soon to be Synology Photos)
  • For Business users who currently enjoy the use of G Suite or Office 365, both of these NAS provide excellent means to backup your mass cloud accounts (as well as natively sync, dupe and configure rules on the fly) with Active Backup Suite and Boxafe
  • Both the QNAP TS-451D2 NAS and Synology DS420+ NAS support snapshots, for more incremental and version protecting failsafe in efforts to protect you from Malware and Ransomware attacks, by allowing multi-versioning storage history to browse through and restore
  • Both the Synology and QNAP NAS allow you to mount cloud services as visible localized storage to interact with on the NAS thanks to HybridMount and HybridShare (DSM 7.0)

  • Both units are DLNA certified so can be accessed, browsed and played from by popular DLNA devices, such as Amazon Firestick, Alexa, Google Home Chromecast, Apple TV, Bose, Sonos, iPads, etc, as well as connectivity between these platforms with IFTTT, though it is certainly worth highlighting that only Synology have dedicated first-party applications for the Alexa and Firestick platform
  • Both are multi-bay, RAID enabled devices NAS devices that support JBOD, RAID 0, RAID 1. RAID 5, RAID 6 and RAID 10 (Synology Hybrid RAID too for the DS420+), as well as supporting the very latest SATA based 16TB and 18TB NAS Hard Drives from brands like WD Red, Seagate Ironwolf, Western Digital UltraStar and Seagate EXOs media.
  • Both devices run on their own proprietary operating system that can be accessed remotely or locally. These include regular updates to the firmware, security patches, applications and more. Ranging from multimedia, home and multi-tiered backup applications, to more business end tools such as Surveillance software, Virtual Machine deployment and business-class backup and synchronization tools. Synology utilize DSM and QNAP use QTS.
  • Both the TS-451D2 and DS420+ use and can be accessed equally by a multitude of mobile applications such as DS File, DS Video, Moments, DS Photo, DSCam and DS Music from Synology, and QFile, QMusic, QVideo, QuMagie and more from QNAP – these are created by and constantly improved by each brand respectively
  • Both NAS are completely compatible with Windows, Android and Mac systems, as well as acting as a bring between software platforms to share and distribute files for migration and file sync
  • Both units can be used as a mail and/or business servers, providing excellent 3rd party CRM and first-party CMS systems on the QNAP NAS platform, as well as the fantastic Synology collaboration Suite of applications Chat, Drive, Mail, Calendar, Office and Active Backup Suite

So, regardless of whether you buy the TS-451D2 or DS420+ NAS, you are going to have a remarkably functional NAS drive. But, let’s dig a little deeper into the differences between these two devices.

Synology DS420+ vs the TS-451D2 QNAP NAS – Design

If you plan on running the NAS server in your local environment (on a desktop or in the corner of your office for example), then there is a chance that design will be an important factor for you. Not only because of the look but also because ventilation, fan noise and space will be a concern. The design of the DS420+ and TS-451D2 are very, VERY distinct and you can certainly see how each brand has imposed its own priorities. The Synology is a great deal sleeker and understated, designed to be set up discreetly (in line with the brand’s internet/network ONLY access priority), whereas the QNAP TS-451D2 is designed to be a bit more stand out, as it has the same internet/network connectivity, but also factors in a few more direct means to access (Keyboard, Video and more or 10G upgradability for editing direct). Additionally, each uses distinct passive cooling measures, with the Synology coming out the more ventilated. Let’s look at each unit (slideshow for each below). First up, the Synology DS420+ Design:

The Synology DS420+ is much more discreet and understand in its chassis. Main highlights are the branded ventilation panels on either side (with further ventilation on the base), as well as the well-separated lockable front trays on the front with plenty of vent space around them. The Chassis design of the DS420+ was been used in the DS920+ before it, as well as a more modern version of the DS416+ 4-Bay generations that came before it, and it has always been very popular. An almost completely plastic external casing that houses the two internal PCBs and metal framework, it still has a very sleek and modern design. The Rear of the DS420+ is largely occupied with twin fan active cooling and it a very clean and appealing design, whether hidden away in a cupboard or out in the open on a desktop. Now, let’s see how that compares with the QNAP TS-451D2 NAS:


The QNAP TS-451D2 design is actually quite similar, but perhaps a little more dated, it is still pretty functional, if not exactly easy on the eye. The passive cooling on the sides and base in not quite so available as the Synology DS420+, but the rear of the system features 1 single, large cooling fan (as opposed to the 2x on the DS420+). This larger fan takes up the bulk of the rear of the NAS and as it has many more ports to accommodate that the DS420+, things do look a little more pushed together. Arguable the QNAP TS-451D2 is a much more functional and desk-ready NAS system, but overall, the Synology DS420+ unquestionably wins the design round in a number of practical and aesthetical ways.


Result – You Should Buy the Synology DS420+ NAS


QNAP TS-451D2 NAS vs the Synology DS420+ NAS – Hardware

Comparing the hardware, both internally and externally, on the DS420+ and TS-451D2 is a remarkably give and take argument. Both systems bring something unique in the hardware department that will benefit different users. As you might well be aware, the DS420+ and TS-451D2 both feature the same CPU, the Intel J4025 Celeron, a dual-core 64bit x86 processor that covers everything from 4K handling, the VMs, Surveillance, multi-user backups, streaming, sharing and supporting DDR4 Memory for increased performance and a large simultaneous rang of services and users at any given time.

This reveals one area where the Synology draws ahead, naming memory frequency (in caveman, ‘speed’). Both systems arrive with 2GB of DDR4 memory, however, the Synology uses 2666Mhz frequency (soldered to the controller board) and the TS-451D2 uses 2400Mhz frequency (2GB SODIMM module in a removable slot). So the Synology DS420+ uses fractionally faster memory, however, the QNAP TS-451D2 immediately counters with the fact it supports up to 8GB of supported maximum memory, whereas the Synology only officially supports 6GB (only having a single available slot to upgrade with and therefore limited to 4GB in the grand scheme of things). Most users would rather choose a larger maximum memory, over a 266MHz memory increase, so even this small victory in hardware by Synology is negligible. After that the hardware featured on the QNAP TS-451D2 is just more varied and allows for many different kinds of user to adapt the system to their own requirements/storage use. let’s look at the hardware specifications below:

Model TS-451D2




CPU Intel® Celeron J4025 dual-core 2.0 GHz processor (burst up to 2.9 GHz)
Intel Celeron J4025 2-core 2.0 GHz, burst up to 2.9 GHz
Benchmark 1946 1946
GPU Intel UHD Graphics 600 (250 – 750 MHz (8GB)) Intel UHD Graphics 600 (250 – 750 MHz (8GB))
RAM 2 GB DDR4 (expandable up to 8 GB) 2400Mhz 2 GB DDR4 (expandable up to 6 GB) 2666Mhz
RAM slots 2X 1X
Cache No Yes, 2x m.2 NVMe SSD Bays
External port • 4 X USB 3.2 Gen 1 (5Gbps)
• HDMI 2.0 (up to 4096 x 2160 @ 60Hz)
• IR Sensor (RM-IR004 Supported)
• 2 X USB 3.2 Gen 1 (5Gbps)
LAN 1 x 1 Gigabit (RJ-45) 2 x Gigabit (RJ-45)

There is one other area of improvement in the DS420+ default model over the TS-451D2 NAS, and that’s the inclusion of NVMe SSD caching bays in the base of the Synology NAS. This is a very ‘Synology’ favoured feature and one that they have been slowly implementing in the bulk of their plus series devices. This allows the system to leverage the high performance (read, write, IOPs, low latency) of the SSDs and use them to improve the repeated file access of the larger capacity, lower priced but slower HDDs in the main bays. The QNAP TS-451D2 does not arrive with this feature, nor does it arrive with a PCIe upgrade slot, so you cannot even add this feature in the system’s lifespan. The QNAP DOES arrive with KVM support (keyboard, video, mouse) parallel access, which is very unique as a feature – especially for those who desire both remote, local and standalone access to their data. It is an especially tricky comparison here, as there are features on either machine that will make it more desirable to different users. However I am inclined to recommend the TS-451D2 NAS over the DS420+ NAS in hardware because you can still technically add SSD caching via SATA 2.5″, it has KVM support, you can upgrade the memory to 8GB rather than 6GB, more USB ports and still arrives at a lower price point.

Result – You Should Buy the QNAP TS-451D2


Synology DS420+ vs the TS-451D2 NAS – Performance

The NAS performance of the Synolgoy DS420+ and TS-451D2 is a much trickier subject to compare. Both because they will behave differently in different user case scenarios AND because they use very different software and file systems. The Synology DS420+ uses DSM and the file system choice of BTRFS (with notable background resource use improvements) or EXT4 (much more history and overall higher performance). The Synology also arrives the more fluid RAID system, Synology Hybrid RAID (SHR) that allows mixed drive utilisation in the RAID configuration – which is very useful in a 4-Bay system, as it allows you to just add 2 drives on day 1 and then later down the line add further HDDs that are a bigger capacity and be able to take advantage of most of it. The QNAP TS-451D2 on the other hand only supports EXT4 and uses only the traditional RAID configurations (JBOD, RAID 0, RAID 1, RAID 5, RAID 6, RAID 10), but as mentioned, also supports direct HDMI monitor, keyboard and mouse support with a parallel GUI/software system for direct access known as HD station (for standalone surveillance, VMs, multimedia playback, office work and hundreds of apps available on the QNAP Club page). Again though, do not overlook the ability to add NVMe SSD for caching in the DS420+. It make seem like a largely unused feature on day 1, but as your NAS use grows, the benefits of cache on a heavily populated system can be impressive. Ultimately, it will come down to how YOU need to use the system. For those considering these two NAS for multimedia, both are a little modest for Plex Media server. They will likely playback the bulk of media for plex (though struggling with H.265/HEVC media for licencing and forced conversion reasons), as well as handling 1080p and 4K transcoding natively quite well (though the QNAP will use more power):

Model TS-451D2


Hardware encryption engine Yes (AES-NI) Yes (AES-NI)
Power 22.08 W / 7.67W 28.30W accessing / 8.45W Hibernate
Codec h264 Decode / Encode Decode / Encode
Codec h265 8bit Decode Decode
Codec h265 10bit NO NO
Codec VP8 Decode / Encode Decode / Encode
Codec VP9 Decode / Encode Decode / Encode
Codec VC-1 Decode Decode
Codec AVC Decode / Encode Decode / Encode

However, a lot of users will be looking to use the Synology DS420+ or QNAP TS-451D2 for numerous tasks at once (in order to maximize their investment) and each system has clear advantages in each area over the other. The Synology DSM system prioritizes their own system and applications over those of 3rd party, leading to some great first-party applications such as the collaboration suite featuring Synology Drive, Chat, Mail, Calendar, Office and more. This is further bolstered with the Active Backup Suite and Hyper Backup tools for synchronization and a tailored, multi-tier backup strategy. QNAP respond with a more balancing 50/50 approach to 1st and 3rd party, with a good range of first-party applications, as well as a larger degree of 3rd party application support (for those that want to use the NAS more for general storage and want to stick with their own pre-existing software. So you have QNAP Mail, Note Station, Calendar, QVR Pro and more, but you also have Office 365 Support, more multiple media player support and diverse VM tools. Next to this they also have backup and sync tools for local/cloud/USB that include Hybrid Backup Sync 3, HybridMount, BoXafe and vJBOD that allow you to make a more 3rd party environment-friendly share/backup/sync hardware environment. Below is a breakdown of key software and performance areas of comparison between the QNAP TS-451D2 and Synology DS420+, which will quickly show you how each system has leveraged it’s brand priorities (in line with what they feel is what their audience want):

Model TS-451D2


Expandability Yes, with 2/4/6/8 Bay Expansion Options No
Surveillance 3 Applications, 8 Camera Licenses 1 Application, 2 Licences
KVM Support Yes No
Browser NVR Camera Access Limited Full
USB Copy Button Yes Yes
Cloud Connectivity HybridMount, HBS 3, BoXafe Hyper Backup, HybridShare, Active Backup Suite
PLEX HD Yes (You will need to upgrade Memory) Yes You will need to upgrade memory)
PLEX 4K Yes (without transcoding) Yes (without transcoding)
Native 1080p Yes (Mostly) Yes (Mostly)
Native 4K Yes (Mostly) Yes (Mostly)
VM Support Yes, Depending on Memory Allocated Yes, Depending on Memory Allocated
Containers Yes, Depending on Memory Allocated Yes, Depending on Memory Allocated
File System EXT4 EXT4 and BTRFS
Backup Types NAS-to-(NAS,PC, Mac, Mobile, USB, Cloud) NAS-to-(NAS,PC, Mac, Mobile, USB, Cloud)

As you can see, although there are marked similarities, the QNAP NAS seems to have a lot more tools and variety of use, whereas the Synology has a more streamline range of services, but chooses to FOCUS on them. There is an argument that you should not half-arse lots of things, choosing to ‘full-arse’ one thing, but then again a lot of users like the open nature of QNAP compatibility and use that the Synology closes off. For a better idea of what each brand provides in terms of the GUI, Photos, Video, Virtual Machines, Backups and Surveillance, I STRONGLY recommend watching one or more of the videos below (open in a new window recommended) as in each I have compared Synology DSM and QNAP QTS on each of these subjects to show their individual strengths and weaknesses:

SYNOLOGY VS QNAP – GUI, System, Apps and User Control

SYNOLOGY VS QNAP – File + File Management & Sharing

SYNOLOGY VS QNAP – Photography and Sharing

SYNOLOGY VS QNAP – Surveillance and NVR use

SYNOLOGY VS QNAP – Home and Business Backups

SYNOLOGY VS QNAP – Virtual Machine Deployment

Ultimately, however, it comes down to the end-user and both the Synology DS420+ and QNAP TS-451D2 have different end-users in mind (as per the brand perspective on the ‘average’ NAS user needs). If you want a complete hardware and software solution that needs little or no 3rd party applications already, then the Synology is likely your best choice. However, if you are looking to buy a NAS that will gel better with your own existing hardware and software, then the QNAP NAS will seem to be a more customizable and versatile tool to your existing environment.

Result – It’s a TIE! Both Have Advantages


QNAP NAS vs the Synology DS420+ NAS – Conclusion

Overall, and this is a tough one, this HAS to be a TIE! I know that sounds like a cop-out, but it really does depend on the needs of the end-user when choosing between the Synology DS420+ and QNAP TS-451D2. The Synology is arguably the better complete-inclusive first-party software solution, but it does this by restricting the way you can use your directories sometimes (needing things to be in pre-set locations) and limiting the range of 3rd party software/hardware you can combine with it. Whereas the QNAP is a much more diverse and open tool that has its own software, but can adapt around our own software/hardware better. This can lead to a slightly steeper learning curve sometimes, but some will be more and able to climb it. Below, if you need a little more closure on the best for each user case, I have detailed which NAS I think is better for each task:

In Summary, if you are looking to buy the DS420+ or TS-451D2 NAS;

Best NAS for Plex Media Server = QNAP TS-451D2 (Thanks to Cayin Player and Compression Support)

Best NAS for Surveillance = QNAP TS-451D2 (Thanks to 8 Camera Licenses and KVM Support)

Best NAS for Virtual Machines = QNAP TS-451D2 (Thanks to More Memory and Virtualization Station)

Best NAS for Photographers = Synology DS420+ NAS (Thanks to Moments, Photo Station and Synology Photos)

Best NAS for Business = Synology DS420+ NAS (Thanks to the Collaboration Suite Apps)


Model QNAP TS-451D2


Synology DS420+




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      17 thoughts on “Synology DS420+ vs QNAP TS-451D2 NAS Comparison

      1. This video could have been better if it didn’t focus so much on your personal preferences. Even though you mentioned several times that it would be up to the user to decide, you constantly propped up Synology and made excuses for it while over-criticizing QNAP’s extensive options. Let the specs and design speak for themselves without so much opinion and bias. This approach would be more effective if the goal is to let the user decide what works best for them.

      2. This video tutorial is from 2020, and since then, DSM 7 has been released. Even more polished and refined User Interface on Synology NAS, which makes Synology a big winner, in my opinion.

        For all Apple fans, Synology seems like a company that could have been acquired by Apple. Same care on the user experience, to make it simple with more advanced options under the hood, but quite hidden, a slow pace for updating the system.

        On the negative side, Synology gets greedier and greedier on hardware and wants to retain more control, hence their difficulties in maintaining a hard drive compatibility list and selling their own hardware.

      3. This looks great, however its now 2022 and I’m looking to get a Synology DS1821+ With I understand DSM 9.x. Any chance of a newer series (or are the differences still not that great to 7.0)?

      4. I’ve only ever used Synology, but truth be known , the GUI always irked me.
        Based on what i’ve seen, the upfront approach of Qnap suits my brain much better.
        Given the way Qnap hardware stands, i will consider adding Qnap devices going forward

      5. Synology wants HOW MUCH for additional cameras? NZD$100 EACH, PLUS SHIPPING?!?! WHY DOES A LICENSE REQUIRE POSTAGE IN 2021!?!?! I can forgive the “you must use our RAM and on premium systems, our drives” thing but selling codes to plug cameras in that cost MORE THAN THE CAMERAS and AREN’T EVEN SUPPLIED ONLINE is fully insane