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

The Synology DS925+ launched in mid-2025 as the direct replacement for the DS923+. On paper it looks like a straightforward upgrade: a faster quad-core CPU, built-in 2.5GbE networking, and a USB-C port. But Synology also quietly removed the PCIe Gen 3 x2 expansion slot, and that single change makes this “upgrade” a downgrade for an entire segment of home lab users.

If you are choosing between these two, the decision comes down to one question: do you want 10GbE networking now or in the future? If yes, the DS923+ is the only Synology 4-bay that can do it. If 2.5GbE is enough for your setup, the DS925+ is the better machine in every other way.

Quick Verdict: Buy the DS925+ New

The Synology DS925+ gets the new-buy recommendation because it is the current, generally available model with a longer remaining support runway. Its built-in dual 2.5GbE is also the better out-of-box network configuration.

The Synology DS923+ remains relevant as a used or clearance option for one specific requirement: its PCIe expansion slot can accept Synology’s 10GbE adapter. Do not pay inflated discontinued-stock pricing just to preserve that option; compare current 5-bay and competing 4-bay products first.

CPU Performance: DS925+ Wins

The DS925+ runs an AMD Ryzen V1500B, a quad-core, 8-thread processor clocked at 2.2 GHz. This chip was originally designed for Synology’s higher-end business NAS units and represents a significant jump over the DS923+‘s dual-core, 4-thread R1600.

In practice, the V1500B’s extra cores matter most for concurrent workloads: running multiple Docker containers, serving files to several users simultaneously, and background tasks like Synology Drive sync, Hyper Backup, and Active Backup. If you regularly push your NAS with parallel operations, the DS925+ handles it with more headroom.

One nuance worth noting: the R1600 can turbo boost to 3.1 GHz on a single core, while the V1500B is locked at 2.2 GHz with no boost. For single-threaded operations, certain backup jobs, package installations, DSM UI responsiveness, the older chip can actually feel snappier. But for the aggregate workload a home lab NAS typically handles, more cores win.

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

Networking: It Depends on Your Ceiling

This is where the comparison gets controversial.

The DS923+ ships with 2x 1GbE ports. That is slow by 2026 standards, 125 MB/s theoretical maximum per port. But it includes a PCIe Gen 3 x2 expansion slot that accepts the Synology E10G22-T1-Mini adapter, giving you 10GbE (1,250 MB/s theoretical). With the adapter installed, the DS923+ has the fastest networking available on any Synology 4-bay.

The DS925+ ships with 2x 2.5GbE ports. That is a 2.5x improvement over the DS923+‘s stock networking, and you can aggregate both ports for a theoretical 5 Gbps link. Out of the box, the DS925+ is significantly faster on the network.

But there is no PCIe slot. No expansion path. 2.5GbE is the ceiling. Forever.

For home lab users building a 10GbE backbone, connecting a NAS to a 10GbE switch alongside a Proxmox host, a workstation, and other infrastructure, the DS923+ with a $130 adapter card delivers 4x the bandwidth of the DS925+. That is not a marginal difference.

If your network is 1GbE or 2.5GbE today and you have no plans for 10GbE, the DS925+ gives you faster networking immediately with zero extra cost or configuration.

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

The PCIe Slot: Why Removal Matters

The PCIe Gen 3 x2 slot on the DS923+ is not just about 10GbE. It is a general-purpose expansion interface. Users have installed 10GbE NICs, additional M.2 SSD adapter cards, and other PCIe peripherals. Synology’s own E10G22-T1-Mini is a plug-and-play solution that DSM recognizes immediately.

Synology’s likely reasoning for removing it: the dual 2.5GbE ports on the DS925+ provide adequate bandwidth for four SATA drives (which max out at roughly 250 MB/s sequential each), and the PCIe slot created overlap with higher-end models like the DS1525+ and RS-series rackmounts.

From Synology’s product strategy perspective, this makes sense. From a home lab user’s perspective, it removes a future-proofing option that was one of the DS923+‘s most compelling features. When you look at the best 4-bay NAS options in 2026, the QNAP TS-464 also offers a PCIe slot at a lower price, making the DS925+‘s omission even more notable.

Winner: DS923+. The PCIe slot alone is a reason to prefer the older model.

RAM and Storage

Both models ship with 4 GB DDR4 ECC SODIMM and support up to 32 GB across two memory slots. ECC RAM is a genuine advantage over competitors like QNAP and ASUSTOR that use non-ECC memory, bit-flip protection matters for a device storing years of data.

Both have 2x M.2 NVMe 2280 slots that support SSD caching or (with DSM 7.2+) dedicated M.2 storage pools. The DS925+ M.2 slots run at PCIe 3.0, same as the DS923+. No difference here.

The DS925+ adds a USB 3.2 Gen 2 Type-C port (10 Gbps) alongside a USB 3.2 Gen 1 Type-A port. The DS923+ has 2x USB 3.2 Gen 1 Type-A ports (5 Gbps each). The Type-C port is a minor convenience for external backup drives but not a deciding factor.

Both support the DX517 expansion unit for an additional 5 bays (up to 9 total), though the DS925+ also works with the newer DX525.

Winner: Tie. Same ECC RAM capacity, same M.2 slots, same expansion bay support.

Software and Longevity

Both run Synology DSM, which is widely considered the best NAS operating system available. The DS925+, as the newer model, will receive DSM updates for longer. Synology typically supports models for 5+ years after launch, so the DS923+ (launched late 2022) will likely reach end-of-life before the DS925+ (launched mid-2025).

The DS925+ shipped with DSM 7.2 and supports DSM 7.3+. The DS923+ also runs DSM 7.3 today, but the DS925+ will receive a few more years of security patches and feature updates.

If you plan to keep your NAS for 7+ years, the DS925+‘s longer support window is worth considering. If your upgrade cycle is 3-5 years, both models will be fully supported during that period.

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

Lifecycle and Availability

Synology’s product-status page lists the DS923+ as discontinued and the DS925+ as generally available. Remaining DS923+ listings may be clearance stock or reseller inventory, so compare the complete cost—including the 10GbE adapter—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 networking on a Synology 4-bay NAS, this is the only way to get it
• You are building a home lab with a 10GbE switch and need your NAS on the same backbone
• You can find a tested used or clearance unit at a defensible total price
• You understand that it is discontinued and are comfortable with a shorter remaining product runway
• You transfer large media libraries, VM images, or backups where 10GbE throughput saves real time

Who Should Buy the DS925+

• 2.5GbE is sufficient for your home network (and for most people, it genuinely is)
• You run multiple Docker containers and want the stronger multi-threaded CPU
• You value a current-generation product with a longer DSM support timeline
• You want faster networking out of the box without buying and installing an adapter card
• You do not have or plan to build a 10GbE network infrastructure

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. Its PCIe slot remains valuable for 10GbE, but that feature does not justify an inflated reseller price. Compare a used DS923+ plus adapter with current QNAP, Synology 5-bay, and DIY alternatives before deciding.

For a broader look at the 4-bay NAS market including QNAP and ASUSTOR alternatives, see our best 4-bay NAS roundup. And if you are comparing Synology against other brands entirely, our Synology vs QNAP guide covers the ecosystem-level differences.