Synology DS923+ vs DS925+: Is the Upgrade Worth It?

The Synology DS925+ arrived in 2025 as the replacement for the DS923+. It brings a faster quad-core CPU and built-in 2.5GbE networking, but Synology also removed the DS923+‘s PCIe network upgrade slot and moved expansion from the DX517 to the DX525. For some home-lab owners, those two changes make the “upgrade” a step back.

The decision comes down to two questions: do you need 10GbE now or later, and do you already own a DX517? If either answer is yes, the DS923+ still has a case. If both answers are no, the DS925+ is the better machine.

Quick Verdict: Buy the DS925+ New

Buy the Synology DS925+ for a new purchase. It is the current, generally available model with the longer support runway, and its dual 2.5GbE beats the DS923+‘s stock networking. Consider a used or clearance Synology DS923+ only when its 10GbE slot or DX517 support is essential, and compare the total cost with current 5-bay and competing 4-bay options first.

CPU Performance: DS925+ Wins

The DS925+ runs an AMD Ryzen V1500B with four cores and eight threads at 2.2 GHz. The DS923+‘s Ryzen R1600 has two cores and four threads at 2.6 GHz, with a 3.1 GHz turbo.

The extra cores matter most for concurrent work: several Docker containers, multiple users, and background jobs such as Synology Drive sync, Hyper Backup, and Active Backup running at the same time.

The R1600 has the higher peak clock, so lightly threaded tasks such as package installs or a single backup job gain less from the upgrade. For the mixed load a home-lab NAS usually carries, more cores matter more.

Winner: DS925+. Twice the cores and threads is a meaningful improvement for NAS workloads.

Networking: It Depends on Your Ceiling

The DS923+ ships with 2x 1GbE, about 125 MB/s per port in theory. Its PCIe Gen3 x2 slot accepts Synology’s E10G22-T1-Mini module, which adds 10GbE (about 1,250 MB/s in theory).

The DS925+ ships with 2x 2.5GbE, two and a half times the DS923+‘s stock per-port speed. Link aggregation can spread traffic from several clients across both ports, although a single transfer still tops out at 2.5 Gbps. There is no PCIe slot, so 2.5GbE is the ceiling.

For a home lab built around a 10GbE switch, with the NAS next to a Proxmox host and a workstation, a DS923+ with the module has four times the per-link bandwidth of a DS925+. If your network is 1GbE or 2.5GbE with no 10GbE plans, the DS925+ is faster out of the box with nothing extra to buy.

Winner: DS923+ for expandability, DS925+ for out-of-the-box speed. For home lab builders who plan to move to 10GbE, the DS923+‘s slot is the more valuable feature.

The PCIe Slot: Why Removal Matters

Synology specifies the DS923+‘s slot as a network upgrade slot and lists the E10G22-T1-Mini as its 10GbE option. Treat it as a 10GbE path, not a general-purpose expansion slot.

The DS925+ has no equivalent. If you want 10GbE and a PCIe slot in four bays, the QNAP TS-464 has a PCIe Gen 3 x2 slot that QNAP lists for optional 5GbE and 10GbE cards; our best 4-bay NAS guide compares it with the other current options. On the Synology side, the five-bay DS1525+ has a network upgrade slot for the same E10G22-T1-Mini module.

Winner: DS923+. The slot is the main reason to prefer the older model.

RAM, Storage and Expansion

Both models ship with 4 GB of DDR4 ECC SODIMM memory and take up to 32 GB across two slots. ECC is an advantage over the Intel Celeron-based 4-bays from QNAP and ASUSTOR in this class, which use non-ECC memory.

Both have two M.2 2280 NVMe slots for SSD cache or M.2 storage pools. Since DSM 7.3 (October 2025), Synology’s 2025 Plus, Value and J models, such as the DS925+ and DS225+, accept third-party 3.5-inch HDDs and 2.5-inch SATA SSDs, but M.2 storage pools and cache still need drives on Synology’s compatibility list.

USB is the same on both: two USB 3.2 Gen 1 ports. The USB Type-C connector on the DS925+ is its expansion port for the DX525, not a data port for external drives.

Expansion is where the two split. The DS923+ connects one DX517 over eSATA, for up to nine drives. The DS925+ connects one DX525 through its USB Type-C expansion port, also for up to nine drives, and Synology lists no DX517 support for it. If you already own a DX517, a move to the DS925+ means buying a DX525 as well; staying on the DS923+ avoids that cost.

Winner: Tie on memory and M.2; DS923+ if you already own a DX517.

Software and Longevity

Both models run DSM 7.4, Synology’s current release. The DS923+ launched in late 2022 on DSM 7.1.1, and the DS925+ launched in 2025 on DSM 7.2.2. Newer hardware stays on Synology’s update path longer: the DSM 7.4 release notes make 7.4 the last upgradable version for several 2016 to 2019 models, including the DS918+ and DS1019+.

If you plan to keep the NAS for seven years or more, the DS925+‘s later start matters. On a three-to-five-year cycle, both should remain supported.

Winner: DS925+. Newer hardware means a longer support timeline.

Lifecycle and Availability

Synology’s product-status page lists the DS923+ as discontinued and the DS925+ as generally available. Remaining DS923+ listings are clearance or reseller stock, so compare the complete cost, including the E10G22-T1-Mini, against current alternatives.

Winner: DS925+. It has a normal current-product channel, while the DS923+ should be evaluated like legacy equipment.

Who Should Consider the DS923+

• You want 10GbE on a Synology desktop 4-bay; the current DS925+ and DS425+ have no slot for it
• You already own a DX517 and want to keep using it
• You are building a home lab around a 10GbE switch and need the NAS on the same backbone
• You can find a used or clearance unit at a defensible total price, including the network module
• You accept a discontinued model with a shorter remaining runway

Who Should Buy the DS925+

• 2.5GbE is enough for your home network (for most homes, it is)
• You run several Docker containers and want the stronger multi-threaded CPU
• You want the current model with the longer DSM support timeline
• You do not own a DX517, or you are ready to move to the DX525
• You have no plans for 10GbE

Bottom Line

The DS925+ is the default new purchase: faster stock networking, a stronger multi-threaded CPU, and a longer support runway. If you are setting up file storage, backups, and Docker services on a 2.5GbE network, buy the DS925+.

The DS923+ is now a specialist legacy option for two groups: buyers who need 10GbE on a Synology 4-bay, and owners of a DX517. Neither justifies an inflated reseller price, so compare a used DS923+ plus the network module with current QNAP, Synology 5-bay, and DIY alternatives before deciding.

For the wider 4-bay market, including QNAP and ASUSTOR, see our best 4-bay NAS roundup. If you are weighing Synology against another brand, our Synology vs QNAP guide covers the ecosystem differences.