Synology J NAS Series Explained – DS120j vs DS220j vs DS420j

DS120j, DS220j or DS420j Which Cheap Synology NAS to Buy? 

For those who are looking at buying their very first NAS drive, or are just looking for a simple network backup to support their existing NAS server, it can be a bit confusing. Synology has made efforts to separate their range of NAS server drives into different categories, in an effort to distinguish which one is most suitable for different applications. Very early on it becomes clear that the Synology J series is the most cost-effective range of devices in their portfolio, however, they have a very similar price and aside from a number of Hard Drive bays, it can be very hard to choose the best budget NAS in 2020. So, we have decided to compare the Synology DS120j 1-Bay, the Synology DS220j 2-Bay and the oldest of the three, the Synology DS420j NAS. Each has its own special buying point (Price, Value, Scalability) and you may be surprised which one best suits your needs. Let’s take a closer look

Value for Money – Synology DS120j vs DS220j vs DS420j

Because you want to buy a budget/cost-effective NAS solution, it will be a big consideration for how much it will cost. Although these three NAS drives are by far the lowest priced Synology NAS devices you can buy in their respective ranges, when compared against each other, the price tag differences are pretty big. In fact, in the jump from 1-bay, to 2-bay and finally to 4-Bay, the price almost doubles each time! The reason for this is threefold.

  1. The number of hard drive bays inside requires a better CPU each time to handle the RAID and communication of users to the larger media
  2. A bigger power supplier is needed each time to support these drives
  3. A bigger chassis is required to house the drives, as well as improved methods of cooling/ventilation to ensure maximum operational temperatures
Synology DS120j NAS

Synology DS220j NAS

Synology DS420j NAS




Most users on a tight budget will want to appropriately divide their budget between NAS hardware and NAS Hard Drive storage (which need to be purchased separately). NAS Hard drives are roughly £30-35 per Terabyte (using Seagate Ironwolf NAS drives as an example), so you will need to factor this in. Although the DS120j is just £90-95, it can only hold 1 hard drive, so you will either need to spend more on a bigger HDD (lose any RAID support too) or limit your long-term storage. Alternatively, you can buy the DS220j at £150+ and either spread the cost of storage across two HDD bays or just populate the NAS with 1 hard drive at the start and add another later. RAID is not your only means of having a safety net and there are numerous ways to back up any of the DS120j, DS220j and DS420j to a USB drive, to another NAS on the network and to 3rd party cloud services like Google Drive and DropBox.

Nevertheless, this leads me to recommend highly that you buy the Synology DS420j NAS as the best NAS for value for money. Although it is by far the most expensive NAS at £290+, you have the option of 4 hard drives and much better hardware options inside that the others (will discuss more below). The clincher is simply the fact you can add hard drives over time, starting with a small drive to start and add bigger and better drives as you need over time. As well as the advantages of a RAID 5 configuration allowing you to have a larger capacity of storage, but still maintain a safety net, the DS420J (and DS220j) supports Synology Hybrid RAID (SHR) so you can add different sized drives and still have a stable device – exceptionally useful for those that want to just install 1-2 drives on day 1 but add more drives later. The DS220j and DS120j NAS both require you to add BIG hard drives at the start in order to ensure long-term storage and this ends up costing you more in the long run.

WINNER – Synology DS420j NAS

You just get alot more for your money. Also, it lets you leverage the cost of HDD and NAS Hardware much better overall.

Synology DS120j vs DS220j vs DS420j – Design

Despite the fact that all three Synology NAS is budget in price, all three have adopted the Synology style very well indeed. NAS drives are designed to be left on for days, weeks and months at a time, so both passive and active cooling is very important. All NAS feature multiple panels of ventilation and an active rear cooling fan, however, although the DS120j and DS220j are very similar (using a near-identical white plastic chassis, non hot-swap drives and a single plastic rear fan), the DS420j is a very different device indeed in terms of design. All three feature dual USB ports (with USB 2.0 on the DS120j) and all three NAS feature the ventilated Synology logo.

Synology DS120j NAS

166 mm x 71 mm x 224 mm

10.04 W (access)
5.01 W (hard disk hibernation)

16.9 dB(A)

Synology DS220j NAS

165 mm x 100 mm x 225.5 mm

17.48 W (access)
7.03 W (hard disk hibernation)

18.2 dB(A)

Synology DS420j NAS

184 mm x 168 mm x 230 mm

21.22 W (access)
8.97 W (hard disk hibernation)

20.6 dB(A)

Straight away, the DS120j and DS220j NAS are the more discreet of the two NAS, with the 1-Bay and 2-Bay being just under 3cm (29mm in fact) different in width. Both use a plastic chassis which lowers operational noise considerably and both are very discreet in terms of size. They even have very similar power consumption, despite their difference in price/size which is always a consideration for heat generation and long-term running. The DS420j, on the other hand, is much bigger in every direction, features a rather dated looking chassis (looks like a 70s cooking appliance but in black) and is a combination of metal and plastic. As much as I want to praise them for the design quality, there is no escaping that the DS420j is the least attractive of the three, is bigger, noisier and generates more heat (even despite those twin rear fans).

WINNER – The Synology DS220j NAS

Although it is very similar to the DS120j, it seems to do a much better job of making the most of that chassis design and makes subtle improvements over the smaller NAS.

Synology DS120j vs DS220j vs DS420j – Hardware

In terms of hardware, the DS120j, DS220j and DS420j have taken similar paths of efficiency and low cost BUT with key evolutionary steps at each tier. We discussed the outside chassis etc earlier, but (like many things) it is what inside that counts! With each price/bay jump between them, the internal CPU power, memory storage and efficiency effectively double with each tier in different locations. See below:

Synology DS120j NAS

Synology DS220j NAS

Synology DS420j NAS

Hardware
Processor model

Marvell Armada 3700 88F3720

Realtek RTD1296

Realtek RTD1296

Processor architecture 64-bit 64-bit 64-bit
Processor clock Dual core 800 MHz Quad core 1.4 GHz Quad core 1.4 GHz
Memory
System memory 512 MB DDR3 512 MB DDR4 1 GB DDR4
Storage device
Number of disk slots 1 2 4
Compatible disk type* (see all supported disks)
  • 3.5″ SATA HDD
  • 2.5″ SATA HDD (with optional 2.5″ Disk Holder)
  • 3.5″ SATA HDD
  • 2.5″ SATA HDD (with optional 2.5″ Disk Holder)
  • 2.5″ SATA SSD (with optional 2.5″ Disk Holder)
  • 3.5″ SATA HDD
  • 2.5″ SATA HDD
  • 2.5″ SATA SSD
Maximum internal net total storage capacity 16 TB (16TB drive x 1) (Capacity varies by RAID type) 32 TB (16TB drive x 2) (Capacity varies by RAID type) 64 TB (16TB drive x 4) (Capacity varies by RAID type)
External connections
RJ-45 1GbE network hole 1 1 1
USB 2.0 port 2
USB 3.0 port 2 2

The CPU on the Synology DS120j is painfully low powered. Do not be fooled by the fact it is a dual-core, it is painfully low powered and even as a network backup drive, it still registers very low speeds indeed.  In fact, all three NAS are ARM processor architecture in design and the DS220j and DS420j are very similar in clock speed (both quad-core, 1.4Ghz per core). However, the big, BIG thing to remember is the fact the DS120j uses a 32bit architecture CPU and the DS220j and DS420j use a 64bit architecture CPU. The difference here is very, very important, as more applications will be able to run on a 64bit processor, as well as it running smoother overall thanks to it’s improved floating-point. This point is further enforced by the better memory present in the DS420j, compared with the other two. There is twice as much RAM in the DS420j than the DS220j and DS120j (though both the 2 bay and 4 bay use DDR4 higher frequency memory modules) which is a massive dealbreaker for 2 reasons. Firstly that a larger amount of memory allows you to host more tasks/users at any time. Second (and I think more crucially) is that the Realtek RTD1296 Processor needs at least 1GB (ideally 2GB to be honest) to really stretch itself (4K transcoding, BTRFS, Snapshots, etc) and although not all of these run tip-top/at all on the DS420j, they will work SIGNIFICANTLY better on the DS420j because of that larger DDR4 memory.

WINNER – Synology DS420j NAS

It is very hard to ignore the faster, more efficient and capable CPU on the DS420j NAS, as well as the higher quantity and quality memory included with this NAS.

Synology DS120j vs DS220j vs DS420j- Software

As you would expect, given the superior hardware featured on the Synology DS420j, it has a much bigger coverage of NAS software in the Synology DiskStation Manager software than the DS120j and DS220j. However, though the DS420j is leaps ahead of the Synology DS120j NAS, it is only fractionally better in terms of software than the DS220j (once again, because of that 512 MegaByte vs 1 Gigabyte Memory) The key advantages are only those where the additional two bays of storage play their part. Below are the key/popular software specs for the three NAS and how they compare:

Synology DS120j NAS

Synology DS220j NAS

Synology DS420j NAS

DSM product specifications
Storage management
Maximum number of iSCSI targets 10 10 10
Maximum number of iSCSI LUNs 10 10 10
Support RAID disk array type
  • Basic
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • Synology Hybrid RAID
  • Basic
  • JBOD
  • RAID 0
  • RAID 1
  • RAID 5
  • RAID 6
  • RAID 10
File sharing
Maximum number of local user accounts 512 1024 1024
Maximum number of local groups 128 256 256
Maximum shared folder 256 256 256
Maximum shared folder synchronization task 2 2 2
Maximum simultaneous CIFS/AFP/FTP connection number 50 100 100
 
Maximum number of simultaneous devices 50 100 100
Maximum number of files carried (ext4) 100,000 100,000
Maximum number of download tasks 20 30 30
Maximum number of files carried 10,000 100,000 100,000
Surveillance Station Yes Yes Yes
Maximum camera support number(camera license required) 5 (with 2 free camera licenses) (View compatible webcam) 12 (with 2 free camera licenses) (View compatible webcam) 16 (with 2 free camera licenses) (View compatible webcam)
Frames per second (FPS) (H.264)* 150 FPS @ 720p (1280×720)
120 FPS @ 1080p (1920×1080)
60 FPS @ 3M (2048×1536)
30 FPS @ 5M (2591×1944)
15 FPS @ 4K (3840×2160)
420 FPS @ 720p (1280×720)
120 FPS @ 1080p (1920×1080)
90 FPS @ 3M (2048×1536)
60 FPS @ 5M (2591×1944)
20 FPS @ 4K (3840×2160)
480 FPS @ 720p (1280×720)
288 FPS @ 1080p (1920×1080)
150 FPS @ 3M (2048×1536)
100 FPS @ 5M (2591×1944)
70 FPS @ 4K (3840×2160)
Frames per second (FPS) (H.265)* 150 FPS @ 720p (1280×720)
150 FPS @ 1080p (1920×1080)
90 FPS @ 3M (2048×1536)
60 FPS @ 5M (2591×1944)
30 FPS @ 4K (3840×2160)
420 FPS @ 720p (1280×720)
210 FPS @ 1080p (1920×1080)
140 FPS @ 3M (2048×1536)
90 FPS @ 5M (2591×1944)
30 FPS @ 4K (3840×2160)
480 FPS @ 720p (1280×720)
288 FPS @ 1080p (1920×1080)
150 FPS @ 3M (2048×1536)
100 FPS @ 5M (2591×1944)
70 FPS @ 4K (3840×2160)
Frames per second (FPS) (MJPEG)* 40 FPS @ 720p (1280×720)
10 FPS @ 1080p (1920×1080)
10 FPS @ 3M (2048×1536)
6 FPS @ 5M (2591×1944)
140 FPS @ 720p (1280×720)
70 FPS @ 1080p (1920×1080)
40 FPS @ 3M (2048×1536)
20 FPS @ 5M (2591×1944)
224 FPS @ 720p (1280×720)
150 FPS @ 1080p (1920×1080)
100 FPS @ 3M (2048×1536)
60 FPS @ 5M (2591×1944)

Straight away the advantages of the Synology DS420j NAS are clear, but given it is almsot twice the price of the DS220j, you do not get twice the coverage of software/clients.Popular applications in the Synology software catalogue, such as Synology Chat, Office, Drive, Mail, Calendar and multimedia apps will funtion on all three devices, but very, VERY basically on the DS120j and with poor performance in any real sense. The DS220j will give you a entry level access in performance to a few of these apps. But there is no denying that the DS420j just has the ability to give you alot more depth with that memory increase. In many cases, the DS220j gives you equal coverage of applications and users to the DS420j, however, it is when you are running multiple apps at once or multiple users that you will see the main difference. The DS420j can support more apps/users at any given time than the DS120j and DS220j, thanks to that more efficient 64bit CPU being facilitated by larger RAM resources, as mentioned earlier (about a million times, I know).

WINNER – Synology DS420j NAS

Not a huge surprise, but it was closer than I thought it would be. You just cannot argue with the increasingly active user numbers and software support of the DS420j over the DS220j and DS120j NAS.

Synology DS120j vs DS220j vs DS420j- Verdict

Given that the Synology DS420j NAS won 3 out of 4 rounds in my budget NAS comparison, it would be easy to just say ‘buy it’, but the truth is a little more complex. Yes, the Synology DS420j is by far the best NAS overall, but for many users, the need for 4 days of storage is just not needed. The same goes for the support of many more simultaneous users, as it might just be 2-3 users at most. If you are looking for genuine future-proofing, then I highly recommend the DS420j. But if you just need a NAS to do a basic amount of everything, then the DS220j will serve you well. Finally, it is worth highlighting that although the Synology DS120j did not win any rounds, it is still a good simple network file server for Hyper Backup or Hyrib Backup sync (using RSync) or a low-level DLNA media server (though ONLY as a target in the former and for only a handful of devices not at once in the latter. Additionally, the DS120j is actually the ‘1-YEAR LATER’ follow up to the DS119j NAS that we tested plenty back in 2018 and it did perform well, even with a staggeringly low 256MB memory. So, food for thought there.

 

Synology DS120j NAS

Synology DS220j NAS

Synology DS420j NAS

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