In keeping with Synology’s two-year refresh cycle, the well-respected DS1520+ 5-bay desktop NAS gets its marching orders to be replaced by the DS1522+ and in this combined review, we stack it up against the new RS422+ rackmount 4-bay model. If you’re in the market for a powerful desktop NAS or a lower-cost general-purpose rack model, we’ll help you make the right buying decision by putting them both through their paces in the lab.
There are a few features common to both models such as the new dual-core 2.6GHz AMD Ryzen R1600 power-plant but the RS422+ represents a new direction for Synology as it strives to offer a more affordable rack mount NAS solution to smaller businesses. The clue is in the name as the ‘4’ indicates that what you see is what you get as far as storage capacity is concerned.
Unlike the more advanced RS822+, it doesn’t have any eSATA ports so can’t be upgraded with Synology’s RX418 4-bay external disk shelf. No such problem with the DS1522+ as it sports dual eSATA ports and can be expanded outside the box to a total of 15 drives using Synology’s DX517 external 5-bay units.
The RS422+ actually resurrects a product line that Synology stopped producing a long time ago. We remember reviewing the RackStation RS411 over ten years ago which was, up until now, Synology’s last 4-bay, non-expandable rack NAS.
DS1522+ and RS422+ specifications
| DS1522+ | RS422+ | |
|---|---|---|
| Form factor | Desktop | 1U rackmount |
| CPU Model | AMD Ryzen R1600 | AMD Ryzen R1600 |
| CPU Architecture | 64-bit x86 | 64-bit x86 |
| CPU Frequency | 2.6GHz | 2.6GHz |
| CPU cores | 2 | 2 |
| Base System Memory | 8GB | 2GB |
| Memory Expandable up to | 32GB (2 x 16GB) | 2GB |
| Memory type | DDR4 ECC SO-DIMM | DDR4 ECC embedded |
| Drive Bays | 5 x LFF/SFF | 4 x LFF/SFF |
| NVMe SSD support | 2 x M.2 NVMe | None |
| USB ports | 2 x USB 3.2 Gen 1 | 1 x USB 3.2 Gen 1 |
| External expansion | 2 x eSATA (DX517) | None |
| Gigabit ports | 4 | 2 |
| 2.5GbE Ports | None | None |
| 10GbE Ports | None | None |
| Expansion slot | PCI-E Gen 3 x2 (T1-Mini card) | PCI-E Gen 3 x2 (T1-Mini card) |
| Power supply | External | Internal |
| Operating System | Synology DSM | Synology DSM |
| Warranty | 3 years | 3 years |
DS1522+ and RS422+ Hardware features
As mentioned previously, both appliances sport the same embedded CPU but there are significant differences in the memory department. The DS1522+ gets you started with a healthy 8GB of DDR4 and the dual SO-DIMM slots tucked away behind its fifth drive bay allow this to be boosted to a very usable 32GB.
The RS422+ is far less accommodating as its modest 2GB of DDR4 is embedded on the motherboard. No spare SO-DIMM slots are provided so this is the maximum supported.
The DS1522+ also supports dual M.2 NVMe SSDs with the 2280 slots easily accessible underneath its chassis behind removable hatches. These can give a performance boost if you’re hosting demanding apps but note that the slots don’t support cheaper M.2 SATA SSDs and unlike similar appliances from Qnap, they can’t be used to create a normal storage pool.
Synology still insists on ignoring the undeniable benefits of 2.5GbE multi-Gigabit network ports so the DS1522+ receives a quartet of Gigabit RJ-45 ports while the RS422+ has two and all support link aggregation for a speed increase. At last, 10-Gigabit comes to Synology’s entry-level appliances as a new feature on both models is a proprietary slot at the rear that accepts Synology’s E10G22-T1-Mini card.
Costing around $187, this small PCI-E Gen 3 x2 card is a bit pricey but it slots neatly into the bay and provides a single 10GbE RJ-45. It’s also worth noting it’s the multi-Gigabit variety so can drop down to speeds of 5GbE, 2.5GbE, and Gigabit.
DS1522+ and RS422+ Build quality
From the front, you’d be hard-pushed to spot any differences between the DS1520+ and DS1522+ as they’re both clothed in the same charcoal-black plastic chassis. You get a row of LEDs down the side showing the status of the appliance and all drive bays while below is a USB 3 port and power button.
Some design changes are evident at the back as the quad Gigabit ports have been moved across to accommodate the 10GbE upgrade card slot. You’ll find the same connector for the large external power supply block while cooling is still handled by dual 9cms diameter fans which, as expected, were found to be exceedingly quiet.
Like its other 4-bay rack brethren, the RS422+ is very well built with a solid steel chassis teamed up with sturdy metal hot-swap drive carriers which accept LFF and SFF devices. Space-poor SMBS will approve of the low profile chassis as at a mere 12.9 inches deep including the rack handles, it’ll fit comfortably in a small wall box or a standard 2-post rack cabinet.
It has three 4cms diameter cooling fans at the rear which we found made very little noise and certainly won’t be noticed in an office environment. There’s little to be gained by removing the lid as you can’t upgrade the RS422+, but underneath you’ll find a compact motherboard with the AMD CPU topped off with a small passive heatsink.
DS1522+ and RS422+ Performance comparisons
For performance testing, we fitted four 14TB WD Red Pro HDDs in the DS1522+ and four 16TB Seagate IronWolf Pro HDDs in the RS422+ with both configured as SHR (Synology Hybrid RAID) arrays. Our test host was a Dell PowerEdge T640 tower server equipped with dual 22-core Xeon Scalable Gold 6152 CPUs, 384GB of DDR4 plus multiple 10GbE ports and running Windows Server 2019.
All our tests were run with the 10GbE upgrade card fitted in both appliances. The DS1522+ is the winner for 10GbE NAS performance with Iometer reporting sequential read and write rates of 1,182MB/sec and 1,172MB/sec. The RS422+ held up well for sequential reads with it delivering 1,080MB/sec but write speeds dropped back to 797MB/sec.
It was the same story for IP SANs with a 500GB iSCSI target on the DS1522+ returning sequential read and write rates of 1,180MB/sec and 1,172MB/sec. Moving to the RS422+ saw read and write speeds of 1,080MB/sec and 710MB/sec.
Both appliances have the same CPU and we suspect the amount of available memory played a big part as Synology’s DSM software performs RAM caching to improve performance. Viewing the DSM Resource Monitor app on each appliance showed that during all tests, the DS1522+ used up to 6.6GB of memory for caching whereas the RS422+ could only present a maximum of 1.5GB.
Differences in our real-world tests were less significant although as expected, the DS1522+ outperformed the RS422+ in all of them. The DS1522+ delivered slightly better speeds for our 25GB large file copy tests, stretching ahead further when securing a 22.4GB folder containing 10,500 small files and during our 25GB copy to an encrypted shared folder.
DSM 7.1 features
Synology’s DSM 7.1 software offers an impressive range of free apps
The AMD CPU in the DS1522+ and RS422+ is the 64-bit variety so there’s nothing on Synology’s DSM menu they can’t run. We’ve always rated DSM highly as it offers an unbeatable range of features and apps with a sharp focus on data protection.
The Storage Manager app provides easy access to all disk-related operations while the separate Snapshot Replication app manages on-demand and scheduled snapshots for NAS shares and thin-provisioned iSCSI LUNs. For further protection, it can run remote replication of snapshots to other Synology appliances.
The Hyper Backup app manages local, remote, Rsync, cloud, and iSCSI LUN backups from a single console and integrates with Synology’s C2 Backup cloud service and a wide range of popular third-party providers for off-site storage. You can create and manage your own private backup cloud as the Drive Server app provides synchronization services for collaboration and file sharing with desktops and mobiles that have the Drive agent installed.
Smart data protection apps allow the appliances to act as central backup vaults
Synology’s Active Backup for Business (ABB) app is a star player as it provides a superb range of data protection facilities for servers, workstations plus virtual environments and the best part is it’s all free. It supports agentless backup services for VMware and Hyper-V virtualization hosts along with application-consistent backups of virtual machines (VMs) and Synology also provides free Active Backup apps for Google Workspace and Microsoft 365.
DSM 7.1 brings the cloud further into play as system configurations can be backed up to your Synology cloud account. It provides access to the Active Insights cloud dashboard which presents system and storage performance data on all registered appliances and once you purchase a premium plan, it’ll add details of all Hyper Backup jobs and alert you to unusual login activity
Synology’s Active Insights cloud service provides remote monitoring for all of its NAS appliances
The only app you can’t run on the RS422+ is Synology’s Virtual Machine Manager as it isn’t available for this appliance – the meager 2GB of memory makes it impractical anyway. No such problems for the DS1522+ as its much higher memory capacity allows you to dish out plenty to your virtual machines.
Both appliances are great candidates for lightweight video surveillance duties and Synology’s Surveillance Station 9 app makes this even more compelling as it is quite simply, the best of its kind. It includes two free IP camera licenses, provides a wealth of camera monitoring, recording plus motion detection features and offers options for uploading recordings to Synology’s C2 cloud service for extra data protection and sharing with other users.
Conclusion
The DS1522+ and RS422+ are similarly priced as after shopping around, we found them both available for around $700. Ultimately, your choice will come down to what you want the appliance to achieve, the workloads it is likely to handle, and, of course, where you want to deploy it.
The RS422+ is a good choice for offices and small businesses that want an affordable rackmount NAS that’s compact enough to tuck away in a small rack or wall cabinet. It works for us as an entry-level backup or surveillance recording vault, it can take advantage of the myriad data protection features available with Synology’s DSM 7.1 software and if you need more network speed, it can be upgraded with the 10GbE adapter card.
Drawbacks of the RS422+ are its modest 2GB of non-upgradeable memory which we found has a negative impact on 10GbE performance and the fact that storage capacity can’t be expanded outside the box. Even so, it does look good value when compared with Synology’s higher-end 4-bay rack NAS models as although the RS822+ offers a lot more hardware features and expansion potential, this will set you back at least $300 more.
If you prefer your network storage on the desk, the DS1522+ won’t disappoint as it packs in a lot more features for a very similar price. Along with five standard drive bays, it can be upgraded with two DX517 expansion units, it supports a high memory capacity, you have dual M.2 NVMe slots should you desire a high-speed cache, and, of course, it supports the new 10GbE upgrade card.
Existing users of the DS1520+ may also be tempted to upgrade as this older model can’t be upgraded to 10GbE. Furthermore, the DS1522+ supports up to four times as much memory which made its presence felt in our 10GbE performance tests and will allow it to run a lot more apps.
Overall, the DS1522+ receives our accolades as it delivers a fine range of features at an affordable price. It’s well built, delivers good 10GbE performance across the board, has plenty of room to grow with future demand, and with DSM 7.1 in the driving seat, offers a remarkable range of apps and data protection services.
