Synology’s Hardware Limits Finally Forced Me to Build a DIY NAS

Outgrowing the NAS I Trusted

The Breaking Point: When Commercial Hardware Meets Stagnant Performance

We have long relied on Synology for reliable network-attached storage solutions. For years, their DiskStation Manager (DSM) offered a seamless user experience, balancing ease of use with essential features. However, as our data requirements grew exponentially—driven by 4K video production, massive photo libraries, and increasingly complex virtualization tasks—the hardware limitations of our flagship Synology units became painfully apparent. The reliance on entry-level and mid-range ARM and Intel Celeron processors, often constrained by PCIe lane limitations and soldered RAM, created a bottleneck that no software optimization could bypass.

The final straw was the realization that the 10GbE network upgrade we implemented was being throttled by the NAS itself. Despite installing compatible 10GbE network interface cards (NICs), the read/write speeds plateaued well below theoretical limits. The culprit was the underpowered CPU, which struggled to handle the overhead of ZFS or Btrfs file systems at high throughput. We were paying a premium for a brand name that promised enterprise-grade features but delivered consumer-grade performance ceilings. The inability to upgrade the RAM beyond 16GB in most consumer models and the strict vendor lock-in on drives (despite marketing claims of compatibility) signaled that we had outgrown the “appliance” model. It was time to pivot to a solution where hardware scalability was not an afterthought but the core design principle.

The Economics of Scale: Cost Analysis of Synology vs. DIY

When analyzing the Total Cost of Ownership (TCO), the disparity between Synology and a custom-built FreeNAS or TrueNAS SCALE system is staggering. A high-end Synology NAS like the DS1821+ retails for approximately $1,000 without drives. This price includes the chassis, motherboard, CPU, and RAM. However, the hardware specs reveal a harsh reality: an AMD Ryzen V1500B processor, which is a low-power quad-core CPU, and 4GB of ECC RAM (upgradable, but at a significant premium).

In contrast, building a DIY NAS allows us to allocate the budget toward high-performance components. For the same $1,000, we can source a server-grade motherboard with IPMI support, a robust Intel Xeon E or Core i-series processor, 32GB of Error Correcting Code (ECC) memory, and a high-airflow chassis. The DIY route eliminates the “Synology tax”—the markup applied to proprietary hardware enclosures. Furthermore, the DIY ecosystem allows us to select specific components that target our workload, such as a motherboard with multiple M.2 NVMe slots for caching or a chassis with hot-swap bays for easy drive maintenance. The cost-per-terabyte efficiency in a DIY build is significantly higher because we are not subsidizing the R&D costs of a proprietary operating system interface.

Hardware Selection: Engineering a High-Performance Server

Selecting the right components is critical to building a NAS that outperforms any off-the-shelf unit. Our strategy focused on three pillars: processing power, memory bandwidth, and storage connectivity.

The CPU: Overcoming the Bottleneck

We moved away from the low-TDP processors found in consumer NAS units. For our build, we selected an Intel Core i5-12500. This processor features integrated UHD Graphics 770, which is vital for Plex transcoding, handling multiple 4K streams without taxing the primary CPU cores. Unlike the soldered CPUs in Synology units, this chip is socketed (LGA 1700), allowing for future upgrades. The multi-core performance outstrips the Ryzen V1500B by a wide margin, ensuring that ZFS calculations (parity checks and deduplication) occur instantly without stalling network transfers.

Memory: The Necessity of ECC

One of Synology’s biggest omissions in consumer lines is the lack of true ECC support. While they market “data integrity,” software-level checksums cannot replace hardware-level error correction. In our DIY build, we utilized 32GB of DDR4 ECC Unbuffered RAM. ZFS, the file system of choice for data integrity, relies heavily on RAM for its Adaptive Replacement Cache (ARC). More RAM means higher cache hits, resulting in snappier file access and reduced wear on SSDs. The ability to scale to 64GB or 128GB on a standard consumer motherboard provides a future-proofing aspect that Synology cannot match.

Storage Controller: HBA vs. RAID Card

Synology relies on proprietary RAID controllers integrated into the motherboard. In a DIY setup, we bypassed the motherboard’s native SATA ports (which are often limited in number) and installed an LSI 9300-8i HBA (Host Bus Adapter) flashed to IT mode. This card acts as a pure passthrough, connecting eight drives directly to the PCIe bus without hardware RAID intervention. This is crucial for ZFS, which demands direct access to the drives to manage data integrity. Using an HBA eliminates the “RAID card lock-in” where a controller failure renders the array unreadable on other systems.

Software Architecture: TrueNAS SCALE vs. DSM

The operating system is the soul of the NAS. While Synology’s DSM is polished, it is also restrictive. We transitioned to TrueNAS SCALE, an enterprise-grade open-source OS based on Linux (Debian). This decision unlocked capabilities that were previously gated behind expensive Synology add-ons.

ZFS: The Gold Standard for Data Integrity

TrueNAS utilizes the ZFS file system, which offers block-level checksumming, snapshots, and self-healing data. When a bit flip occurs on a drive, ZFS detects it and repairs it using parity data—provided you are using a redundant array (RAID-Z2, similar to RAID 6). Synology’s Btrfs is a capable file system, but it lacks the maturity and performance tuning of ZFS. In our testing, ZFS on TrueNAS provided significantly faster scrub speeds and more granular control over dataset compression (LZ4) and deduplication.

Virtualization and Containerization

Synology Docker support is functional but limited by the hardware we previously used. With the i5-12500 and 32GB ECC RAM, TrueNAS SCALE allows us to run lightweight Kubernetes clusters natively. We migrated our internal services—including a PostgreSQL database and a Redis cache—directly onto the NAS. The ability to mount NFS or SMB shares directly into containers provides a unified storage and compute solution that a Synology unit could never handle without external hardware.

Networking: 10GbE and Beyond

TrueNAS SCALE makes configuring Link Aggregation (LACP) and 10GbE networking straightforward. We utilized a 10GbE SFP+ NIC (Intel X710) to connect to our core switch. The performance jump was immediate. Large file transfers that took minutes on the Synology now saturate the 10GbE link (approx. 1.1 GB/s). The overhead of the OS is minimal, ensuring that the CPU focuses on data transfer rather than managing network bottlenecks.

Chassis and Cooling: The Unsung Heroes

A NAS runs 24/7, making thermal management and acoustic performance vital. Synology chassis are compact but often run hot, leading to premature fan failure.

The Case: Fractal Design Node 804

We selected the Fractal Design Node 804. This case is legendary in the DIY NAS community. It features a dual-chamber design: one chamber for the motherboard, CPU, and PSU, and a separate chamber for up to eight 3.5-inch drives. This separation ensures that the heat from the drives does not affect the CPU cooling, and vice versa. The airflow is directed specifically to keep drive temperatures in the optimal 30-40°C range, preventing thermal throttling.

Power Supply: Efficiency and Redundancy

Power supply selection was prioritized for efficiency at low loads. We utilized an 80 Plus Gold modular PSU. Unlike Synology units that use proprietary power bricks, a standard ATX PSU offers higher wattage headroom for adding more drives or GPUs in the future. For critical environments, a DIY build can accommodate a redundant (dual) PSU setup via specialized power distribution boards, a feature usually reserved for expensive rackmount units.

Building the ZFS Pool: Configuration for Maximum Safety

The heart of the DIY NAS is the storage pool. In DSM, creating a storage pool is a few clicks, but the underlying configuration is opaque. In TrueNAS, we have full control.

Choosing the Right VDEV Layout

We configured our pool using RAID-Z2. This requires a minimum of four drives but allows for two simultaneous drive failures without data loss. Unlike Synology’s SHR (Synology Hybrid RAID), RAID-Z2 does not suffer from write speed penalties during rebuilds. We organized our drives into a single VDEV (Virtual Device) of eight drives. This setup balances storage capacity (approx. 60% usable space) with safety.

SSD Caching: L2ARC and SLOG

To further accelerate performance, we added two NVMe SSDs. One is dedicated as a SLOG (Separate Log) device, which accelerates synchronous writes (crucial for virtualization and databases). The second acts as an L2ARC (Level 2 Adaptive Replacement Cache). While ZFS prefers RAM for caching, L2ARC provides a secondary layer of flash storage for frequently accessed data that doesn’t fit in RAM. This configuration is rarely possible on consumer Synology units without purchasing expensive proprietary expansion cards.

Security and Remote Access: Enterprise Features for Free

Security was a major concern when leaving the walled garden of Synology.

VPN and Reverse Proxy

Synology’s QuickConnect is convenient but introduces latency and relies on Synology’s relays. In our DIY setup, we established a WireGuard VPN server directly on TrueNAS. This allows for secure, high-speed remote access to our files and services without exposing ports to the open internet unnecessarily. For web-based interfaces (like Nextcloud or Photoprism), we configured an Nginx Reverse Proxy with automated SSL certificate renewal via Let’s Encrypt.

User Management and Permissions

TrueNAS utilizes Unix-style permissions combined with Windows ACLs (Access Control Lists). This provides granular control over user access, surpassing the basic user groups in DSM. We integrated LDAP (Lightweight Directory Access Protocol) to centralize user credentials across our network, ensuring that the NAS adheres to our existing domain security policies.

The Migration Process: Moving Data Safely

Transitioning from Synology to DIY requires a meticulous migration strategy to prevent data loss. We did not simply “drag and drop” files.

1. Phase 1: Build and Burn-in: We assembled the hardware and ran stress tests (MemTest86 and BadBlocks) for 72 hours to ensure component stability before transferring any data.
2. Phase 2: Dataset Structure: We replicated the folder structure on the new TrueNAS system, setting up SMB shares with identical names to minimize disruption for end-users.
3. Phase 3: Incremental Sync: Using Rsync over SSH, we performed an initial full sync from the Synology to the TrueNAS. This preserved file attributes and permissions.
4. Phase 4: Delta Sync: We scheduled a final delta sync during a maintenance window. Once verified, we decommissioned the Synology unit.

Long-Term Maintenance and Scalability

A DIY NAS is not “set it and forget it,” but the maintenance is manageable and transparent.

Drive Health Monitoring

TrueNAS utilizes SMART (Self-Monitoring, Analysis, and Reporting Technology) tests more aggressively than DSM. We configured email alerts to notify us immediately of any drive anomalies, such as reallocated sector counts or high temperatures. This proactive monitoring allows us to replace a drive before it fails, a feature Synology has but is less customizable.

Scalability

The most compelling reason for the DIY build is future scalability. If we need more storage, we can add a HBA card and a drive cage. If we need more compute for AI image recognition, we can swap the CPU or add a GPU. The motherboard has unused PCIe slots; the case has empty bays. This contrasts with Synology, where “upgrading” usually means buying an entirely new unit and migrating the drives.

Conclusion: The Freedom of Self-Hosting

The transition from Synology to a DIY NAS was driven by hardware limits but resulted in a liberation of capability. We traded the “appliance” mindset for an enterprise-grade infrastructure that we fully control. The initial investment in time and research paid off in performance, data integrity, and long-term cost savings. For professionals who view storage not just as a repository but as a critical component of their workflow, building a custom NAS is the only viable path forward. The constraints of proprietary hardware are no longer a barrier; the potential of our storage infrastructure is defined only by the hardware we choose to install.