Synology DS1525+ NAS Review

Synology DS1525+ NAS Review – A Solid Release, with bizarre compatibility rules

The Synology DS1525+ is the latest entry in the company’s long-running 5-bay Plus series, designed to deliver a flexible and reliable storage solution for small businesses, creative professionals, and advanced home users who require more capacity and functionality than entry-level models but do not need a full enterprise rackmount system. Retaining the familiar compact desktop chassis of its predecessor, the DS1522+, the DS1525+ supports up to 15 drives with two DX525 expansion units and integrates two M.2 NVMe slots for SSD caching or storage pools, catering to workloads that demand higher IOPS and tiered performance. Notably, it moves away from the Ryzen R1600 CPU found in the DS1522+, opting instead for the quad-core AMD Ryzen V1500B, a server-oriented processor that prioritizes file processing and ECC memory support over integrated graphics and media transcoding. This change aligns the system with Synology’s broader SMB product strategy, which emphasizes data integrity and predictable performance under multi-user access rather than consumer-oriented multimedia features.

The DS1525+ also introduces dual 2.5GbE ports, replacing the DS1522+’s four 1GbE ports, and retains a PCIe Gen3 ×2 slot for optional 10GbE network upgrades. These hardware refinements are paired with Synology’s DSM software platform, which continues to offer one of the most comprehensive and secure NAS operating environments on the market. However, as highlighted in testing and the accompanying video review, these benefits are tempered by Synology’s increasingly restrictive hardware validation policies, which limit drive and SSD compatibility and impose artificial constraints on expandability. This review examines the DS1525+ from multiple angles, including design, internal hardware, connectivity, software functionality, and overall value, to help prospective buyers determine whether its trade-offs and strengths align with their needs.

Synology DS1525+ NAS Review – Quick Conclusion

The Synology DS1525+ is a dependable and well-executed 5-bay NAS that strikes a careful balance between reliability, expandability, and ease of use, making it particularly suited for small businesses, creative professionals, and advanced home users looking for a scalable and predictable storage solution. It builds on Synology’s proven design, offering a compact and quiet chassis with hot-swappable drive bays, support for up to 15 drives with expansion units, and efficient cooling that maintains low noise levels even under sustained workloads. Powered by the quad-core AMD Ryzen V1500B processor and equipped with ECC memory—expandable to 32 GB—the DS1525+ handles multi-user file serving, virtualization workloads, and surveillance duties with stability and consistency. The dual rear 2.5GbE ports, with link aggregation and optional 10GbE via the PCIe slot, offer a meaningful upgrade path for network throughput, while the two M.2 NVMe slots allow for SSD caching or dedicated storage pools, further enhancing performance in I/O-heavy tasks. DSM remains one of the most comprehensive and user-friendly NAS operating systems on the market, providing seamless integration of backup, hybrid cloud, collaboration, virtualization, and security tools that save significant administrative time and deliver strong data protection. However, the system also reflects several compromises: the PCIe Gen3 ×2 mini slot limits the bandwidth and physical scope available to high-speed expansion cards, USB ports are restricted to basic storage and UPS use, and NVMe performance is constrained by Synology’s validated SSD options that prioritize endurance over maximum throughput. Furthermore, the transition from four 1GbE ports on the DS1522+ to two 2.5GbE ports on this model sacrifices some redundancy and may necessitate infrastructure upgrades to take full advantage. Despite these limitations, the DS1525+ remains a solid choice for users already invested in Synology’s ecosystem, or for those who value predictable hardware behavior, mature software integration, and quiet, efficient operation over unrestrained hardware flexibility. In environments where DSM’s feature-rich platform and long-term stability are more critical than maximum raw performance or third-party hardware freedom, the DS1525+ delivers a consistent and refined experience.

SOFTWARE - 10/10

HARDWARE - 6/10

PERFORMANCE - 7/10

PRICE - 7/10

VALUE - 6/10

7.2

PROS

👍🏻Compact and quiet 5-bay design with support for 15 drives total
👍🏻Dual 2.5GbE ports with aggregation and optional 10GbE upgrade
👍🏻ECC memory support with upgradable capacity up to 32 GB
👍🏻Hot-swappable drive bays and tool-free tray design
👍🏻Integrated M.2 NVMe slots for caching or storage pools are easy to access, tooless and uncomplicated to deploy
👍🏻Excellent DSM software suite with extensive features
👍🏻Stable performance under multi-user and virtualized workloads
👍🏻Efficient cooling with low noise levels in office environments

CONS

👎🏻Huge limitations on the choice of HDD and SSD Media you can use on this system
👎🏻USB ports limited to basic storage/UPS functionality
👎🏻M.2 NVMe performance has limited scope in current configuration and support

Synology DS1525+ NAS Review – Design and Storage

The DS1525+ continues Synology’s established design language, using a compact desktop enclosure measuring 166 × 230 × 223 mm and weighing just under 2.7 kg. The chassis is predominantly plastic on the exterior, with a metal internal frame to support the drive bays and improve rigidity. Although it retains the same overall appearance as the DS1522+, the DS1525+ benefits from thoughtful airflow improvements that enhance thermal performance under sustained workloads. Ventilation is provided by dual 92 mm rear-mounted fans, complemented by side and base vents to maintain consistent internal temperatures even with all five bays populated and two NVMe SSDs installed. The toolless 3.5” drive trays allow quick installation of SATA HDDs without screws, while optional brackets support 2.5” SATA SSDs if required. As noted during testing, the physical build remains sturdy and understated, making it a good fit for office and studio environments where noise and visual distraction are concerns.

In terms of storage flexibility, the DS1525+ supports five native drive bays, each hot-swappable, and accepts a mix of 3.5” SATA HDDs and 2.5” SATA SSDs. The bays are managed by Synology’s DSM software and support all common RAID configurations, including SHR, RAID 5, 6, and 10, enabling users to optimize for capacity, redundancy, or performance depending on their workload. The system can also scale up to 15 drives using two DX525 expansion units, connected via dedicated USB Type-C expansion ports on the rear. Although the move from eSATA to USB-C modernizes the connection standard, it does not significantly increase bandwidth, as it remains limited to approximately 5 Gbps per link, which can become a bottleneck if the expansion units are fully populated with high-speed drives. Despite this, the expandability remains useful for businesses that anticipate growing data storage needs over time, allowing gradual investment rather than a large upfront commitment.

A key design inclusion is the two M.2 2280 NVMe slots located on the underside of the chassis. These slots can be configured as read/write cache for improved random I/O performance or, with Synology’s verified SSDs, as dedicated storage pools. In testing, the NVMe slots were confirmed to operate at PCIe Gen3 ×4 per slot, providing ample bandwidth for most NAS-grade SSDs. However, as pointed out in the video review, the available Synology NVMe SSDs are endurance-oriented and limited in write speed, which may undercut the full potential of these slots for high-throughput storage pools.

The slots also remain restricted by Synology’s SSD validation policy, which prevents the use of competing brands and forces users to choose from Synology’s own range of NVMe drives, which are often more expensive and limited in capacity. Nonetheless, the M.2 slots provide additional flexibility for workloads that benefit from caching or tiered storage setups, particularly in virtualized or database-heavy environments. Another important design consideration is the thermal and acoustic behavior of the DS1525+ when fully populated and under sustained load.

During extended testing with five 7,200 RPM Synology HAT5300 HDDs and two NVMe SSDs, surface temperatures remained within acceptable ranges, averaging 38–43°C around the chassis and 65–70°C on the NVMe drives. The rear fans were able to maintain stable temperatures across the system even with high drive activity, and they support multiple fan profiles (Quiet, Cool, Full-Speed) for users to balance noise and cooling performance. The plastic chassis construction helps keep overall noise levels lower than metal-bodied alternatives, with measured idle noise between 36–39 dBA and peak noise under heavy load reaching around 52–55 dBA when using high-RPM drives. While not silent, it is unlikely to be disruptive in most office or home environments, especially when placed out of direct proximity to users.

Lastly, the DS1525+’s storage features are tightly integrated with Synology’s DSM platform, which supports a maximum single volume size of up to 108 TB (or 200 TB with sufficient memory). RAID migrations, volume expansions, and global hot spares are supported across all common RAID types, making it easy to adjust storage configurations as needs change. For businesses, the ability to expand storage on demand, coupled with snapshot and replication tools in DSM, ensures data resiliency and flexible recovery options. However, the strict hardware validation policy remains a limitation; users migrating from older systems with non-Synology drives may encounter warnings, inability to expand arrays, or even outright initialization failures with unsupported drives. This policy makes it essential to plan storage purchases carefully and verify compatibility prior to deployment.

Synology DS1525+ NAS Review – Internal Hardware

At the heart of the DS1525+ is the AMD Ryzen V1500B processor, a quad-core, eight-thread 64-bit CPU running at 2.2 GHz. This server-class embedded chip is designed primarily for file processing and multi-threaded workload stability, and its inclusion aligns with Synology’s focus on predictable performance and ECC memory support over multimedia capabilities. Unlike the Ryzen R1600 found in the earlier DS1522+, which offers higher clock speeds and integrated graphics, the V1500B omits hardware media encoding and transcoding support entirely, reflecting Synology’s deliberate pivot toward business-oriented file operations rather than consumer-grade media streaming.

The processor is soldered to the mainboard and not user-replaceable, but it provides sufficient compute power for services like Btrfs snapshots, high-volume SMB/NFS file serving, virtualization with up to eight recommended VM instances, and running multiple DSM applications simultaneously. Its support for ECC memory is particularly valuable in critical environments where data integrity is paramount, reducing the risk of corruption during power events or high load.

The system is equipped with 8 GB of DDR4 ECC SODIMM memory as standard, installed as a single 8 GB module. The motherboard provides two SODIMM slots, supporting up to 32 GB of total memory using 16 GB modules in a dual-channel configuration. This memory ceiling is adequate for typical SMB workloads, virtualization, and even moderate database applications, though users with heavier VM demands or larger hybrid cloud deployments may want to upgrade early. Synology strongly recommends using only validated Synology memory modules, as DSM will display warnings if unvalidated modules are detected, and technical support may be limited. During testing, the standard 8 GB configuration was sufficient for running DSM with multiple file shares, virtual machines, snapshot tasks, and background indexing processes without hitting memory bottlenecks. The memory can be easily accessed and upgraded by removing the side panel of the chassis, which is designed for straightforward maintenance.

Thermally, the DS1525+ maintains internal component stability even under full load. The processor is passively cooled, relying on the dual rear 92 mm fans for airflow across the entire system. Temperature readings during stress tests remained within specification, though the V1500B’s higher TDP compared to Intel Atom or Celeron CPUs results in slightly elevated baseline power consumption. The internal layout remains organized and clean, with the M.2 slots located on the underside of the chassis, separate from the mainboard and drive bays. This prevents localized hotspots and allows the fans to maintain airflow across all critical components, including memory and storage. Users should note that while the PCIe Gen3 interface supports expansion cards, the available slot is limited to ×2 link width, reflecting the moderate bandwidth needs of most NAS workloads but potentially constraining advanced 10GbE or multi-SSD configurations. The overall hardware architecture reflects a deliberate balance between cost efficiency, reliability, and the target workload profiles Synology intends for this model.

Synology DS1525+ NAS Review – Ports and Connections

The DS1525+ offers a streamlined set of connectivity options that aim to balance modern bandwidth requirements with compatibility and expandability. On the rear panel, the system features two RJ-45 2.5GbE network ports that replace the four 1GbE ports found on the DS1522+. These ports support link aggregation, failover, and SMB Multichannel for improved throughput and redundancy, but users will need a compatible 2.5GbE or multigigabit switch to fully realize their potential.

For users requiring more network bandwidth, Synology provides a PCIe Gen3 ×2 expansion slot that can accommodate an optional 10GbE NIC, allowing the system to scale up to much higher transfer rates when used in demanding environments such as large media libraries or high-concurrency file sharing. This combination of onboard 2.5GbE and optional 10GbE caters to a wide range of deployment scenarios, though the move from four ports to two may disappoint users who previously relied on the additional ports for VLAN separation or increased failover granularity.

In addition to networking, the DS1525+ includes two USB 3.2 Gen 1 Type-A ports, positioned on the rear, which support basic external storage and UPS connections. Unlike earlier models that offered limited support for USB accessories, the DS1525+’s USB implementation is largely relegated to these basic functions, and it does not support more advanced use cases like external GPUs or high-speed data ingest beyond the capabilities of USB 3.2 Gen 1. The USB ports are adequate for attaching backup drives or monitoring UPS status but are otherwise limited in functionality. Adjacent to the USB ports are two USB Type-C expansion ports that allow connection of up to two DX525 expansion units. While the move to Type-C modernizes the connector form factor, these expansion ports are still based on a SATA-equivalent bandwidth of roughly 6 Gbps per link, limiting their aggregate performance potential. Nonetheless, they enable storage scalability from five to 15 bays, maintaining a clear upgrade path without requiring a complete system replacement.

Physically, all ports are located on the rear panel, keeping the front of the chassis clean and accessible for drive access. The PCIe slot is located internally, and installing an expansion card requires removing the top panel. Users who need the optional 10GbE NIC should plan for this additional step during setup. Power input is handled through an internal 120W AC adapter, eliminating the need for an external brick and contributing to the system’s tidy cabling.

The system also supports Wake-on-LAN and power recovery, allowing administrators to automate power cycles and recover from outages remotely. The inclusion of two 2.5GbE ports reflects Synology’s incremental approach to adopting higher-speed Ethernet standards while maintaining affordability, but it also highlights the relatively modest ambitions of this generation when compared to competitive NAS units that have already adopted four-port 2.5GbE or standard 10GbE onboard configurations.

Synology DS1525+ NAS Review – Speed, Noise and Power Consumption Tests

The DS1525+ demonstrates controlled acoustic performance that is in line with its intended use in office or home environments. The dual 92 mm rear fans operate in three selectable profiles — Quiet, Cool, and Full-Speed — allowing users to adjust the balance between noise and cooling efficiency. During testing with five Synology HAT5300 7,200 RPM drives and two NVMe SSDs installed, idle noise levels were measured at approximately 36–39 dBA in Quiet mode, which is noticeable but unlikely to disturb most users. Under moderate load in Cool mode, noise levels increased slightly to around 37–40 dBA, while Full-Speed mode produced more airflow and reached approximately 43–45 dBA with minimal vibration. Peak noise occurred when the drives were under heavy access and the fans at maximum speed, reaching 52–55 dBA. As noted in the video review, at that point the drive mechanics themselves were more audible than the fans, especially when using high-RPM or larger capacity HDDs. Overall, the system remains suitable for placement in proximity to users as long as larger enterprise-grade drives are avoided.

In terms of power consumption, the DS1525+ is modestly more efficient than earlier generations, though still higher than lower-power Celeron-based alternatives due to the Ryzen V1500B’s higher baseline TDP. In the lowest idle state with no drives installed, the system consumed approximately 16.7–16.8 watts, which can be further reduced through DSM’s scheduled hibernation features. With five 4TB 7,200 RPM drives installed and idle, power draw increased to around 41–42 watts. During active workloads with all drives accessed simultaneously and a 10GbE NIC installed, power consumption peaked at roughly 60–68 watts, which is reasonable given the system’s capacity and workload. When tested using only the SSD storage pool over 10GbE, power draw settled between 53–58 watts, reflecting the efficiency of the NVMe SSDs but also the fact that the Ryzen CPU remains engaged during high-throughput operations. These figures highlight that while the DS1525+ is not among the most power-frugal NAS options, it remains within acceptable limits for its class.

Performance testing covered several storage configurations and network scenarios to evaluate throughput and responsiveness. Using five Synology HAT5300 drives in SHR and a Synology E10G22-T1-Mini NIC installed for 10GbE connectivity, sequential read speeds reached 900–950 MB/s, with write speeds peaking around 800–850 MB/s. This demonstrates that the system can effectively saturate a 10GbE link under optimal conditions with HDD-based arrays. Using only the two onboard 2.5GbE ports with link aggregation, the system achieved approximately 550–580 MB/s combined, which is sufficient for many SMB workloads but falls short of single 10GbE capabilities. NVMe performance was limited by Synology’s validated SSDs, which prioritize endurance over speed, reaching maximum write speeds around 750 MB/s and read speeds closer to 1,000 MB/s in a RAID 0 pool. As noted in testing, higher-performing third-party SSDs are not supported due to validation restrictions, which prevents the system from fully exploiting the NVMe slots’ Gen3 ×4 bandwidth potential.

For real-world mixed workloads, the DS1525+ proved capable of handling simultaneous file sharing, virtual machine hosting, and snapshot operations without significant degradation. Virtualization workloads supported up to eight recommended VM instances, and Surveillance Station operated within specification at up to 40 1080p cameras, though sustained workloads at maximum capacity may benefit from additional memory. File transfers over SMB maintained consistent throughput even under multiple concurrent sessions, and Btrfs snapshot and replication tasks completed within expected timeframes for the test array. The system’s stability and predictability align well with business-focused deployment scenarios, provided users adhere to the validated hardware list and plan network infrastructure accordingly. The key limitations in performance stem not from the hardware itself but from the imposed compatibility restrictions, which may prevent users from selecting higher-performing drives or SSDs.

Synology DS1525+ NAS Review – DSM Software

The DS1525+ runs Synology’s DiskStation Manager (DSM) operating system, which remains a cornerstone of its appeal. DSM combines an intuitive web-based interface with a rich suite of business, backup, collaboration, and security applications that are deeply integrated into the hardware. The operating system leverages the DS1525+’s hardware capabilities fully, supporting Btrfs as the default file system for internal volumes, providing snapshot-based recovery, advanced quota management, and replication options. In this model, DSM supports up to 32 internal volumes, 108 TB per volume (expandable to 200 TB with 32 GB of memory), and all common RAID configurations including SHR for flexible redundancy. File services are comprehensive, with SMB, AFP, NFS, FTP, Rsync, and WebDAV all included, as well as support for Active Directory, LDAP, and Kerberos authentication. The user and group management features allow up to 1,024 user accounts and 256 groups, making it suitable for departmental and SMB environments.

DSM’s package ecosystem enables the DS1525+ to function as more than just a file server. The system supports core Synology applications such as Active Backup for Business, which allows centralized backup of PCs, servers, and cloud services, and Synology Drive, which offers private cloud-style file sharing with file versioning and team collaboration. Hyper Backup facilitates multi-version backups to local or remote destinations, while Surveillance Station turns the NAS into a capable NVR, supporting up to 40 cameras at 1080p. Virtualization workloads are handled through Virtual Machine Manager, which supports up to eight recommended VM instances and integrates with VMware, Windows Server, and Citrix environments. The DS1525+ also supports Snapshot Replication, Hybrid Share for hybrid cloud workflows, and Synology Office and Chat for internal collaboration. The ecosystem continues to prioritize stability, security, and ease of management, which explains its popularity even in the face of growing hardware restrictions.

That said, DSM’s strength also highlights the ongoing tension between software capability and Synology’s restrictive hardware validation policies. The DS1525+ enforces validated drive and SSD lists for full functionality of features like RAID recovery, hot spares, and SSD storage pools. While DSM continues to outperform many competitors in usability and features, these artificial restrictions reduce hardware choice and increase costs. Prospective users should review Synology’s compatibility list before deploying third-party drives, especially if migrating from older systems. For those willing to adhere to Synology’s ecosystem, DSM delivers a mature, reliable platform that simplifies even complex workflows, while maintaining strong security practices and a steady cadence of updates.

Synology DS1525+ NAS Review – Verdict and Conclusion

The Synology DS1525+ is a capable and well-built NAS that continues the company’s focus on dependable performance, solid build quality, and integration with the robust DSM software ecosystem. Its compact 5-bay design, quiet operation, and scalable storage make it a suitable choice for small offices, creative studios, and prosumers who need reliable data management with room to grow. The inclusion of a server-grade Ryzen V1500B CPU and ECC memory support ensures predictable performance for file serving, virtualization, and surveillance workloads, while the dual M.2 slots and PCIe expansion keep it competitive in terms of flexibility. DSM remains a standout feature, providing an excellent range of tools for backup, collaboration, and hybrid cloud deployments that can save significant time and administrative effort in day-to-day use. From a hardware standpoint, it represents a moderate but clear improvement over the DS1522+ in terms of network bandwidth and workload readiness, even if some areas, like PCIe bandwidth and USB functionality, have seen little or no change.

However, the DS1525+ also reflects several limitations inherent in Synology’s current approach. The switch from four 1GbE ports to two 2.5GbE ports sacrifices some port redundancy and may require infrastructure upgrades to fully benefit. The reliance on validated Synology drives and SSDs, while arguably aimed at improving stability and support, adds cost and restricts flexibility, which can frustrate users migrating from existing hardware ecosystems. In performance terms, while the DS1525+ can saturate a 10GbE link under the right conditions, the full potential of its NVMe slots and PCIe expansion is hampered by both validation policies and hardware link width. Ultimately, this NAS is best suited for those already invested in Synology’s ecosystem or those who value software integration and ease of use over hardware openness. For buyers who prioritize predictability, software maturity, and a controlled experience, the DS1525+ delivers on its promises. For those who want maximum hardware freedom or higher outright performance for the price, competing options may be worth considering.

Synology DS1525+ NAS
Amazon in Your Region for the Synology DS1525+ NAS @ $799	B&H for the Synology DS1525+ NAS @ $1149.99

 

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