The catch
Synology DiskStation DS1825+
A suitable shelf and clearance are needed for the 343 mm width.
Side by side
Synology DS1825+ vs DS1525+: The CPU and RAM ceiling are the same, while eight bays fit a larger archive
Quick verdict
Go with the DS1825+ if you need six to eight SATA drives in one chassis, or if a supported 25GbE card is in your plans. The DS1525+ is the better fit when five internal bays are enough and the narrower chassis helps. Their published Ryzen V1500B, 8 GB ECC starting memory and 32 GB maximum are the same, so the bigger model mostly differs in storage and expansion hardware.
Before you buy
Why, and what it costs you
Adding a sixth drive can spare you a whole expansion box
Six SATA drives fit inside DS1825+ with two bays still free, whereas DS1525+ has five internal positions.
Where this comes from
Two is what eight minus six leaves. A six-drive layout is one more than five.
The catch
Synology DiskStation DS1525+
The original enclosure holds just five SATA drives inside.
Synology DiskStation DS1825+
- Why pick it
- House six to eight SATA drives in one chassis
- Go to 25GbE through the documented PCIe route
- The catch
- A suitable shelf and clearance are needed for the 343 mm width.
Synology DiskStation DS1525+
- Why pick it
- Take the narrower chassis with five bays
- Add the optional E10G22-T1-Mini to get 10GbE
- The catch
- The original enclosure holds just five SATA drives inside.
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What this page compares
See how DS1825+ and DS1525+ differ on holding six drives without an expansion box, a 25GbE upgrade and how wide a shelf you have.
Go with the DS1825+ if you need six to eight SATA drives in one chassis, or if a supported 25GbE card is in your plans. The DS1525+ is the better fit when five internal bays are enough and the narrower chassis helps. Their published Ryzen V1500B, 8 GB ECC starting memory and 32 GB maximum are the same, so the bigger model mostly differs in storage and expansion hardware.
Which one fits
Pick the situations that sound like you
Six SATA drives have to stay in the original chassis
Five internal bays are on DS1525+.
- Synology DiskStation DS1825+
- Better fit
- Synology DiskStation DS1525+
- Not suitable
Go through a documented 25GbE card route
A 10GbE mini module is documented for DS1525+.
- Synology DiskStation DS1825+
- Better fit
- Synology DiskStation DS1525+
- Not suitable
Fit within a 320 mm wide opening before any added clearance
Widths of 343 mm and 230 mm apply to the chassis.
- Synology DiskStation DS1825+
- Not suitable
- Synology DiskStation DS1525+
- Better fit
Begin with 8 GB of ECC memory
That configuration comes with both selected packages.
- Synology DiskStation DS1825+
- Good
- Synology DiskStation DS1525+
- Good
In practice
Differences you will notice
Adding a sixth drive can spare you a whole expansion box
Six SATA drives fit inside DS1825+ with two bays still free, whereas DS1525+ has five internal positions.
How we worked this out
Two is what eight minus six leaves. A six-drive layout is one more than five.
Planning on 25GbE means choosing the larger card platform
Compatible 25GbE network cards are documented for DS1825+, and the 10GbE mini-module route is documented for DS1525+.
How we worked this out
Dual 2.5GbE is where both begin, and a faster connection takes an additional supported adapter.
With a 320 mm shelf opening, one of the chassis is out
Published widths are 343 mm and 230 mm. DS1525+ alone fits within a 320 mm opening before extra clearance.
How we worked this out
343 minus 320 gives a 23 mm overrun, and 320 minus 230 leaves 90 mm before ventilation or handling allowances.
Option A
Synology, DS1825+
Synology DiskStation DS1825+
ECC memory and eight SATA bays, plus a supported PCIe route to 10GbE or 25GbE networking.
- Best for
- House six to eight SATA drives in one chassis
Facts we checked
- SATA bays inside: 8
- Width of chassis: 343 mm
- Network ports built in: Two 2.5GbE
- Route to faster networking: A supported PCIe 10GbE or 25GbE card
Option B
Synology, DS1525+
Synology DiskStation DS1525+
It offers five SATA bays, dual native 2.5GbE and ECC memory, plus a separate 10GbE mini-module for upgrading the network.
- Best for
- Take the narrower chassis with five bays
Facts we checked
- SATA bays inside: 5
- Width of chassis: 230 mm
- Network ports built in: Two 2.5GbE
- Route to faster networking: The optional E10G22-T1-Mini, for one 10GbE port
Spec by spec
Where they really differ
| Spec | Synology DiskStation DS1825+ | Synology DiskStation DS1525+ | In practice |
|---|---|---|---|
| Internal SATA bays | 8 | 5 | The smaller chassis limit is crossed by a six-drive requirement. |
| Chassis width | 343 mm | 230 mm | The shelf also has to leave room for ventilation and cables. |
| Native network ports | Two 2.5GbE | Two 2.5GbE | Neither one has 10GbE as standard. |
| Faster-network expansion | Supported PCIe 10GbE or 25GbE card | Optional E10G22-T1-Mini for one 10GbE port | The two upgrade formats cannot be used in place of each other. |
| Processor and supplied memory | Ryzen V1500B, 8 GB ECC | Ryzen V1500B, 8 GB ECC | Base processor and RAM specs match. |
| Maximum supported RAM | 32 GB | 32 GB | Neither documented memory ceiling is higher than the other. |
| SATA bays with two optional DX525 units | 18 | 15 | Two additional enclosures and drives are needed to reach those totals. |
Trade-offs
What each pick costs you
With Synology DiskStation DS1825+
- An additional compatible card is required for faster Ethernet.
With Synology DiskStation DS1525+
- The dedicated network module route on it ends at the documented 10GbE option.
Change of plan
When the answer changes
Either six to eight internal SATA drives or 25GbE is required
Go with Synology DiskStation DS1825+. The larger internal layout and card route come with DS1825+.
Five bays are enough, and shelf width matters
Go with Synology DiskStation DS1525+. DS1525+ comes in 113 mm narrower.
I require supported RAM above 32 GB
Neither model fits. Each publishes a 32 GB maximum.
Decision guide
How to decide
Pick the DS1525+ when five internal bays are enough and you can use its narrower chassis. Pick the DS1825+ when six to eight SATA drives have to stay in one chassis, or when a supported 25GbE card is planned. Since the Ryzen V1500B, 8 GB ECC starting memory and 32 GB maximum are published identically for both, the larger model’s gains are in storage and expansion hardware.
Adding a sixth drive can spare you a whole expansion box
An archive that already calls for six drives stays inside one NAS chassis on the DS1825+. On the DS1525+ you would need a different drive plan or a separate supported expansion unit. Compare whole enclosures, including power connections and cabling. None of this recommends spanning a storage pool across enclosures, and it promises no in-place migration.
Planning on 25GbE means choosing the larger card platform
When your workstation and switch setup needs 25GbE, pick the model with documented card support and check the exact adapter. On a 10GbE network, both have an upgrade path, though the card format is different. Don’t put a generic PCIe card in the mini-module slot, and don’t expect 25GbE out of the DS1525+ 10GbE accessory.
With a 320 mm shelf opening, one of the chassis is out
Measure the actual opening, and leave the cooling and service access the manufacturer requires. In this example the wider DS1825+ doesn’t fit even before any extra clearance is added. The smaller model has the same published processor, starting ECC memory and memory ceiling, so a five-drive job doesn’t necessarily give up any of those resources by choosing the narrower enclosure.
What this page can’t tell you
- Throughput, noise, power and application behavior were not compared in matched tests. The expansion-bay totals count DX525 units that you buy separately.
By the numbers
What the data shows
What we found across the NAS devices we compare, plus the checked facts behind each finding.
Show the facts and the math
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Synology DiskStation DS1825+ |
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| Synology DiskStation DS1525+ |
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Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
Synology DiskStation DS1825+
House six to eight SATA drives in one chassis
See price & reviews on AmazonSynology DiskStation DS1525+
Take the narrower chassis with five bays
See price & reviews on AmazonEach link opens in a new tab.
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