Synology DiskStation DS423+: compatible drives
By Devin Chua · Data checked by Owen Nakamura · Updated For the Synology DiskStation DS423+ fit CMR NAS drives like WD Red Pro or Seagate IronWolf Pro across all 4 bays up to 96 TB raw. Synology's 2025 drive policy applies only to models launched from 2025, so the DS423+ takes third-party hard drives and 2.5-inch SATA SSDs as it always has. At 4 × 8 TB the DS423+ keeps 21.83 TiB usable in SHR, about CA$2,288 in drives. Since its Intel Celeron J4125 (4 cores) hardware-transcodes Plex through Intel Quick Sync and runs a stack of containers, with a light VM or two as the ceiling, buy the DS423+'s drives on price and quietness, not speed.
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Want to know whether the DS423+ fits your actual storage plan? Open the NAS Builder with this model weighted.
What fits the DS423+
| Drive type | Status | Detail |
|---|---|---|
| 3.5-inch SATA hard drive (CMR) | Fits | Synology publishes no per-drive size limit; its compatibility list shows tested sizes. |
| 2.5-inch SATA SSD | Fits | The bays take 2.5-inch drives. |
| SAS drive | Does not fit | The bays are SATA; a SAS drive needs a SAS controller. |
| SMR hard drive | Avoid in RAID | Works alone, but can stall a rebuild for days. Check the model number against the maker's CMR/SMR list. |
| M.2 SATA SSD (for example WD Red SA500 …R0B) | Does not fit | Not a bay drive, and the M.2 slots take NVMe only. |
| M.2 NVMe SSD | Listed drives only | The DS423+'s 2 M.2 slots take 2280 NVMe drives, and Synology's compatibility list for it names only its own SNV3400, SNV3410 and SNV5420 drives, which Synology requires for both cache and storage pools. |
How we decide what is compatible
A part reaches our shortlist for the DS423+ only when it meets Synology’s published specifications for its form factor, interface, size and memory type, and, where Synology requires its own compatibility list (as Synology does for M.2 NVMe), when it is on that list. Parts that fit physically but are not on a required list are shown separately and labelled. Parts that depend on a detail Synology does not publish are labelled “fit not confirmed”. Anything that does not fit is left out. Our methodology explains each step.
Sources for the DS423+: global.synologydownload.com (read 2026-10-05); www.synology.com (read 2026-10-05); kb.synology.com (read 2026-10-05).
Current offers: the drives, memory and NVMe that pass these rules, with Amazon.ca prices, are on the best drives for the DS423+ page and its memory and NVMe pages.
The Synology drive policy on the DS423+
unrestrictedOpen. The 2025 restriction does not apply retroactively; every NAS drive works.
The DS423+ at a glance
| Bays | 4 × 3.5-inch SATA and 2.5-inch SATA SSD |
|---|---|
| Maximum raw capacity | 96 TB 4 × 24 TB: the largest drive on Synology's list for this model. The often-quoted 108 TB is the maximum volume size, not the sum of drives. |
| Processor | Intel Celeron J4125 (4 cores) |
| Memory | 2 GB, DDR4 SO-DIMM, no ECC (2 GB soldered plus 1 slot) 6 GB official (2 GB fixed plus a 4 GB module). In practice a 16 GB module runs (giving 18 GB); Synology does not endorse it. |
| M.2 NVMe | 2 slots 2 × M.2 NVMe for cache; an NVMe storage pool requires a Synology drive |
| Network | 2 × 1GbE |
| Operating system | DSM 7.x |
| RAID types | SHR, SHR-2, Basic, JBOD, RAID 0, RAID 1, RAID 5, RAID 6, RAID 10 SHR also makes use of mixed drive sizes. |
Keep calculating
To see how much capacity is left after parity, the DS423+ capacity calculator is preset to its 4 bays and RAID types. For the DS423+, the wider basics of choosing a drive are in the buying guides, and CMR versus SMR explains why SMR drives do not belong in a RAID array. Wondering what the DS423+ can actually do: Plex, Immich, Docker, VMs? See what the DS423+ can run.
Frequently asked questions
Can I put third-party drives in the DS423+?
Yes. Synology's 2025 drive policy applies only to models launched from 2025, so the DS423+ takes third-party hard drives and 2.5-inch SATA SSDs as it always has.
Which drives fit the DS423+?
The DS423+ takes any 3.5-inch SATA and 2.5-inch SATA SSD drive; use a CMR NAS family rated for 24/7 duty such as IronWolf, WD Red Plus or Toshiba N300. On its 2 × 1GbE, even a basic 5400 rpm drive saturates the DS423+'s link.
How much capacity is usable in the DS423+?
In the DS423+, 4 × 8 TB in SHR gives about 21.83 TiB usable and survives 1 drive failing; the balance is parity.
Can the DS423+ run Plex with hardware transcoding?
Yes. The DS423+'s Intel Celeron J4125 (4 cores) includes Intel Quick Sync, which hardware-transcodes Plex including 4K HEVC, so it handles several streams at once without loading the CPU.
Is a Pro drive worth it in the DS423+?
Not for speed. The DS423+'s 2 × 1GbE caps throughput near 110 MB/s, which the cheapest NAS drive already reaches, so a Pro drive only buys the longer warranty and higher workload rating.
Devin Chua works out which drives, RAM and NVMe cache fit which NAS model at nasdrives.ca, and what the RAID choice means for usable capacity, checked against what is in stock on Amazon.ca.
Data checked by Owen Nakamura, Technical editor (data checking)