Synology DS1525+ vs DS1522+ NAS

Synology DS1525+ vs DS1522+ NAS Comparison – Get It Right, FIRST TIME!

With the arrival of the Synology DS1525+ in 2025, many users are now weighing it against its immediate predecessor, the DS1522+, released in 2022. On the surface, both NAS units share the same 5-bay form factor, nearly identical chassis design, and very similar price points—typically between $699 and $799 at launch. However, a deeper dive reveals a number of meaningful changes in hardware resources, storage expansion policies, and how Synology now handles drive compatibility and system flexibility. While the DS1525+ does offer better networking and CPU core count, it also introduces tighter restrictions on what drives can be used, how storage pools are formed, and what options are available to users looking to migrate data from older systems. By contrast, the DS1522+ retains a far more open approach to hardware, offering greater freedom for enthusiasts and IT professionals. In this article, we’ll break down the internal hardware, ports, storage support, DSM software capabilities, and system behavior of these two NAS systems—giving you the context you need to make the right decision the first time, and avoid buyer’s regret later.

Synology DS1525+ vs DS1522+ NAS Comparison – Internal Hardware

The most noticeable hardware difference between the DS1525+ and DS1522+ lies in their processors. The DS1522+ is powered by a dual-core AMD Ryzen R1600 CPU, which operates at a base frequency of 2.6 GHz and can boost up to 3.1 GHz. This chip delivers strong single-threaded performance and is very power efficient, making it well-suited for environments where tasks are sequential or lightly parallelized—such as SMB file sharing, surveillance, or general-purpose storage. The DS1525+, in contrast, uses a quad-core AMD Ryzen V1500B processor running at a fixed 2.2 GHz. While it lacks boost frequency, the additional cores and threads make it the more capable option for multitasking-intensive DSM deployments. Workloads like hosting multiple Docker containers, running several VMs, or operating high-volume backup jobs are handled more smoothly by the V1500B thanks to its stronger concurrent throughput. While synthetic benchmarks might show the R1600 ahead in single-threaded operations, in day-to-day NAS usage, the V1500B’s multitasking benefits are more relevant—particularly for users aiming to centralize many services on one box.

Component	Synology DS1522+	Synology DS1525+
CPU Model	AMD Ryzen R1600	AMD Ryzen V1500B
CPU Architecture	64-bit, Dual-Core, 4-Thread	64-bit, Quad-Core, 8-Thread
Base / Turbo Frequency	2.6 GHz / 3.1 GHz	2.2 GHz (no boost)
Hardware Encryption	AES-NI	AES-NI
Pre-installed Memory	8 GB DDR4 ECC SODIMM (1×8 GB)	8 GB DDR4 ECC SODIMM (1×8 GB)
Total RAM Slots	2	2
Max Supported Memory	32 GB (2×16 GB)	32 GB (2×16 GB)
ECC Support	Yes	Yes
System Cooling	2 × 92mm fans	2 × 92mm fans
Noise Level (Idle)	22.90 dB(A)	22.60 dB(A)
Power Supply	120W External Adapter	120W External Adapter
Power Consumption (Access)	52.06 W	44.56 W
Power Consumption (Idle)	16.71 W (HDD Hibernation)	13.63 W (HDD Hibernation)
Chassis Dimensions (H×W×D)	166 × 230 × 223 mm	166 × 230 × 223 mm
Weight	2.7 kg	2.67 kg

Memory configurations between the two models appear similar at first glance. Both ship with 8 GB of DDR4 ECC SODIMM memory installed in a single stick and support up to 32 GB using both slots. ECC memory is a staple of Synology’s Plus series, designed to catch and correct single-bit memory errors on the fly—an important safeguard in RAID arrays, collaborative file editing, and database hosting. However, in practical use, the DS1525+ has more headroom to take advantage of this memory due to its quad-core CPU, making it more responsive when multiple DSM services are running concurrently. For example, users running Surveillance Station with 10+ cameras, Synology Drive, and a virtual DSM guest will find the DS1525+ holds up better under load, whereas the DS1522+ may begin to show bottlenecks unless its RAM is upgraded early. Despite these differences, both systems provide adequate memory for general use and can be expanded easily if workload demands grow.

Beyond raw processing and RAM, the DS1525+ also refines power and noise efficiency. It has a slightly lower noise floor at 22.60 dB(A) compared to the DS1522+ at 22.90 dB(A)—a small but welcome reduction for those placing the NAS in workspaces or home offices. Power consumption is another area of subtle improvement. The DS1525+ draws just 44.56 watts under active use and 13.63 watts in HDD hibernation, making it more efficient than the DS1522+, which consumes 52.06 watts and 16.71 watts, respectively. This improvement may be attributed to internal board optimizations and more efficient firmware tuning. Physically, both NAS systems share identical chassis dimensions, cooling layout, and component arrangement, including dual 92mm fans for thermal management. In sum, while neither model introduces radical hardware changes over the other, the DS1525+ provides a better balance of multitasking power and efficiency for modern DSM deployments—particularly when scaling beyond light usage.

Synology DS1525+ vs DS1522+ NAS Comparison – Ports and Connections

The differences between the DS1525+ and DS1522+ become more apparent when examining their networking and expansion connectivity. The DS1522+ is equipped with four 1GbE RJ-45 LAN ports, which support link aggregation for up to 4 Gbps combined bandwidth when used with a managed switch. This configuration provides solid redundancy and flexible port allocation, especially for environments where isolating traffic across different services (e.g., backups, media, surveillance) is desirable. However, in 2024 and beyond, 1GbE is increasingly viewed as a bottleneck—particularly for users working with 4K video editing, large VM images, or fast local backups. The DS1525+ addresses this issue by shifting to 2 × 2.5GbE RJ-45 LAN ports, allowing up to 5 Gbps total bandwidth through link aggregation, and faster speeds on a per-connection basis, even when using unmanaged 2.5GbE switches that are now more common and affordable. This change aligns the DS1525+ with modern mid-tier NAS expectations and offers improved real-world performance, especially for multi-user workloads and high-speed transfers from SSD caches or NVMe pools.

Feature	Synology DS1522+	Synology DS1525+
LAN Ports	4 × 1GbE RJ-45	2 × 2.5GbE RJ-45
Link Aggregation / Failover	Yes	Yes
USB Ports	2 × USB 3.2 Gen 1	2 × USB 3.2 Gen 1
Expansion Ports	2 × eSATA (for DX517)	2 × USB Type-C (for DX525)
PCIe Slot	1 × PCIe Gen3 x2 (for 10GbE upgrade)	1 × PCIe Gen3 x2 (for 10GbE upgrade)
Wake on LAN / WAN	Yes	Yes
Scheduled Power On / Off	Yes	Yes
Hot-Swappable Drive Bays	5 × SATA HDD/SSD (M.2 not hot-swappable)	5 × SATA HDD/SSD (M.2 not hot-swappable)
M.2 NVMe Slots	2 × M.2 2280 (cache only, 3rd-party SSDs supported)	2 × M.2 2280 (cache and storage, Synology SSDs only)
Expansion Compatibility	DX517 (eSATA interface)	DX525 (USB-C interface)

In terms of USB connectivity, both models include two USB 3.2 Gen 1 ports, suitable for attaching external drives, UPS units, or compatible USB printers. These ports remain unchanged between models and offer no direct performance advantage to either system. Where the expansion capability does change significantly is in the port type for connecting additional storage enclosures. The DS1522+ includes two eSATA ports, allowing it to connect up to two DX517 expansion units, adding 10 more drive bays. The DS1525+, however, replaces these with two USB Type-C expansion ports, which interface with the newer DX525 expansion units. While the overall expansion capacity remains the same (15 total bays), the move to USB-C reflects a generational shift in Synology’s design language. USB-C may offer slightly more flexible cable routing and future-proofing, but it also introduces a hard cutoff between older and newer ecosystems. For users with existing DX517s or other eSATA-based gear, this limits backwards compatibility and locks the DS1525+ into the latest hardware infrastructure.

Additionally, both units include a PCIe Gen3 x2 slot for optional 10GbE network upgrades. Synology’s E10G22-T1-Mini card is supported on both models and provides a compact, cost-effective way to future-proof network performance. However, given the DS1525+ already starts with 2.5GbE, users may find less urgency to upgrade immediately compared to the DS1522+, where a 10GbE card may be needed sooner to break past 1GbE limitations. Both models support Wake-on-LAN and scheduled power events, and both feature dual rear fans for effective cooling regardless of network traffic or drive load. From a connectivity standpoint, the DS1525+ represents a forward step toward higher-speed networking and modern expansion methods—but it does so at the cost of legacy compatibility, which may matter for users with established infrastructure. In contrast, the DS1522+ offers broader port coverage and flexibility but risks becoming dated more quickly in high-throughput environments.

Synology DS1525+ vs DS1522+ NAS Comparison – Storage

At first glance, storage capacity and physical layout appear virtually identical between the DS1525+ and DS1522+. Both systems offer five main drive bays that support 3.5″ SATA HDDs and 2.5″ SATA SSDs, as well as two M.2 NVMe SSD slots for caching or, in the case of the DS1525+, full storage pool creation. Each NAS can be expanded up to a total of 15 bays using two proprietary Synology expansion units (DX517 for the DS1522+, DX525 for the DS1525+), enabling up to 240 TB of raw storage assuming maximum capacity drives. However, a major divergence emerges when we examine drive compatibility policies. The DS1522+ follows Synology’s older, more permissive approach: users may install third-party drives from brands like Seagate, Western Digital, or Toshiba with only warning messages shown during setup. Storage pools, RAID arrays, and DSM installation all proceed without functional restrictions, making it a flexible platform for users with existing drives or cost-sensitive deployments.

Further separating the two models is support for NVMe-based storage pools. The DS1522+ only allows M.2 NVMe SSDs to be used for read/write caching, and it permits the use of third-party SSDs for this function, giving users a cost-effective route to performance acceleration. The DS1525+, however, allows these NVMe slots to be used for full DSM storage volumes—but only when using Synology-verified SNV-series SSDs. This enables the creation of fast, low-latency storage pools using NVMe media, which is a compelling advantage for certain workflows (like media scratch disks or high-speed sync folders). Still, the restricted compatibility policy limits practical utility for those who already own quality NVMe drives from other vendors. In short, while the DS1525+ technically offers more advanced storage architecture, the DS1522+ offers far more freedom, especially for users managing legacy systems, migrating data from older Synology devices, or sourcing their own HDDs and SSDs independently.

Synology DS1525+ vs DS1522+ NAS Comparison – DSM Capabilities

Both the DS1525+ and DS1522+ run Synology’s DSM 7.2 operating system and provide access to the same broad library of official and third-party packages. This includes core applications such as Synology Drive for file sync and access, Synology Office for collaborative documents, and Active Backup for Business for system-wide backup management. The app experience is largely identical on both devices, with support for Virtual Machine Manager, Hyper Backup, Snapshot Replication, Synology Photos, and Surveillance Station. However, the differences in system hardware and compatibility enforcement subtly influence how DSM behaves and what features remain available under different configurations. For example, both models support up to 256 snapshots per shared folder and a system-wide maximum of 4,096 snapshots, but users on the DS1525+ will be subject to stricter compatibility enforcement in DSM’s Storage Manager if using drives that aren’t on Synology’s approved list.

DSM Feature / Capability	Synology DS1522+	Synology DS1525+
DSM Version	DSM 7.2+	DSM 7.2+
Max Internal Volumes	64	32 ▼
Max Single Volume Size	108 TB	200 TB (requires 32 GB RAM) ▲
Snapshot Replication	256 per shared folder / 4,096 total system snapshots	256 per shared folder / 4,096 total system snapshots
Synology Drive Users	Up to 60	Up to 80 ▲
Synology Office Users	Up to 60	Up to 80 ▲
Virtual Machine Manager (VMs)	Up to 4 Virtual Machines	Up to 8 Virtual Machines ▲
Virtual DSM Instances (Licensed)	Up to 4	Up to 8 (1 free license) ▲
Hybrid Share Folder Limit	10	10
Surveillance Station (H.265)	40 cameras / up to 1200 FPS	40 cameras / up to 1200 FPS
Maximum SMB Connections (RAM Expanded)	30	40 ▲
RAID Recovery with 3rd-Party Drives	✅ Supported	❌ Blocked
Storage Expansion with Unverified Drives	✅ Supported	❌ Blocked
Hot Spare (Unverified Drives)	✅ Supported	❌ Blocked
M.2 NVMe Caching (3rd-Party SSDs)	✅ Supported	❌ Blocked
NVMe Storage Pool Creation	❌ Not supported	✅ Supported (Synology SNV SSDs only)
DSM Storage Manager Behavior (Unverified)	Warnings only, all features functional	Persistent alerts, blocks expansions and rebuilds
High Availability Support	Yes	Yes
Full System Backup (Hyper Backup)	Yes (DSM 7.2+)	Yes (DSM 7.2+)

Where this becomes particularly relevant is during system migration or advanced storage scenarios. The DS1522+ handles drive migration and unverified HDDs without functional limitation. DSM will display minor warnings but still permit RAID recovery, storage pool expansion, hot spare assignments, and cache creation—even with mixed-brand hardware. By contrast, the DS1525+ introduces active blocks within DSM for unsupported drives. Users migrating from older Synology NAS devices using drives like WD Red Plus or Seagate IronWolf will find that, while the DS1525+ may import the pool, DSM will flag the drives as unverified and prevent future RAID rebuilds or expansions unless all disks are from Synology’s supported list. These alerts cannot be disabled, and they will persist across the user interface, making the system appear at risk even if the drives themselves are healthy. This creates a significant difference in administrative experience, especially for IT professionals managing multiple systems or resellers integrating legacy hardware.

In terms of user and service scalability, the DS1525+ supports slightly higher limits overall. It allows for up to 80 Synology Drive users and Office users (versus 60 each on the DS1522+) and can support up to 8 concurrent virtual machines versus 4 on the DS1522+, assuming sufficient RAM is installed. Surveillance Station camera and FPS limits are virtually identical, and both models support High Availability, Hybrid Share, SAN Manager, and central management features. However, the DS1525+ supports larger single volume sizes—up to 200 TB if upgraded to 32 GB RAM—compared to the DS1522+’s 108 TB ceiling. In return, the DS1522+ offers more internal volume flexibility with support for up to 64 volumes, double the DS1525+’s 32 volume limit. This trade-off reflects Synology’s shifting priorities in DSM: the DS1525+ favors fewer, denser volumes and more centralized control, while the DS1522+ gives power users finer-grained storage separation. Both systems excel with DSM, but your experience will differ depending on whether you prioritize scalability and structure—or open, hardware-flexible operation.

Synology DS1525+ vs DS1522+ NAS Comparison – Conclusion

The Synology DS1525+ and DS1522+ may look nearly identical on the outside, but they diverge sharply in philosophy, system behavior, and long-term value. The DS1522+, launched in 2022, stands as one of the last truly flexible 5-bay NAS systems in Synology’s portfolio. It offers a dual-core AMD Ryzen R1600 processor with excellent single-thread performance and supports up to 15 drives with two DX517 expansions. More importantly, it retains the traditional Synology approach to third-party drive compatibility—meaning users can install and operate a wide range of HDDs and SSDs (Seagate, WD, Toshiba, etc.) without system blocks. DSM will issue warnings if a drive isn’t officially listed, but critical features like RAID recovery, storage pool expansion, and hot spare assignment continue to function. That level of hardware openness makes the DS1522+ particularly attractive to power users, budget-conscious builders, and small IT teams looking to repurpose existing hardware. The DS1525+, released in 2025, represents a subtle but significant shift in Synology’s design strategy. On paper, it offers solid upgrades: a quad-core AMD Ryzen V1500B processor that enables better multitasking, faster 2.5GbE LAN ports for improved data throughput, lower noise and power consumption, and full NVMe storage pool support (with Synology SSDs). These improvements make the DS1525+ a better fit for users running multiple simultaneous services—such as Surveillance Station, Synology Drive, and Docker containers—all while maintaining smooth operation. However, these benefits come with stricter limitations. The unit enforces Synology’s 2025-era drive verification policy, which outright blocks DSM installation or RAID operations with unverified drives. Migration is allowed, but users will be met with persistent warnings, degraded system status indicators, and feature restrictions that can’t be bypassed. The flexibility to reuse older drives, expand arrays freely, or mix hardware brands has been systematically curtailed.

In essence, the choice between these two NAS systems reflects more than just performance—it’s a decision between openness and control. The DS1522+ remains a strong all-rounder for users who want to build their system on their own terms, manage diverse storage needs, or repurpose hardware they already trust. It’s well-suited to small businesses, creators, and experienced users who value transparency and adaptability. The DS1525+, by comparison, is more refined, but also more prescriptive. It favors users willing to commit fully to Synology’s ecosystem—those who prioritize simplicity, tighter integration, and long-term consistency, even at the expense of flexibility. It’s a better fit for turnkey environments where reliability and vendor support matter more than customization. Both NAS devices are excellent in their own right, but the right choice depends entirely on how much control you’re willing to trade for convenience—and whether your NAS should be a platform you shape, or a solution that shapes your workflow.

Aspect	Synology DS1522+	Synology DS1525+
✅ Pros	– Broad 3rd-party HDD/SSD compatibility	– 2.5GbE LAN ports for faster networking out of the box
	– Fully supports RAID recovery, expansion, and hot spares with any drive	– NVMe SSDs can be used for storage pools (Synology SSDs only)
	– Better suited for drive migration from older NAS systems	– Quad-core CPU enables better multitasking and virtualization
	– More internal volumes supported (up to 64)	– Lower power draw and slightly quieter operation
	– Ideal for budget-conscious users and mixed-brand deployments	– Slightly higher user caps in DSM apps (Drive, Office, VMM)
❌ Cons	– Only 1GbE networking unless upgraded	– Blocks DSM install and critical functions with unverified drives
	– No support for NVMe storage pools	– Only Synology SSDs supported for caching or NVMe volumes
	– Lower VM performance ceiling (dual-core CPU)	– Fewer internal volumes supported (32 max)
		– Less suitable for users with existing 3rd-party storage hardware
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