Synology DS1621+From real comments

Verdict distilled from 32 mentions across 13 aspects in comments under product review videos.

Positive sentiment63%
PROS 63%
CONS 37%

Rank based on 32 mentions across 13 aspects

View the verdict as

Buy this if...

  • You want an expandable 6-bay NAS with room for RAM, NVMe cache, and 10GbE upgrades
  • You need reliable storage for backups, VMs, or Synology Drive collaboration
  • You value Synology's software ecosystem over raw CPU horsepower

What users love

Skip this if...

  • You need built-in GPU/hardware transcoding for smooth 4K Plex streaming
  • You want cutting-edge CPU or default 10GbE networking out of the box
  • You've been burned by Synology's proprietary drive/HDD policies before

What users complain about

Compare in seconds

Based on user comments

Best choice
1Mid
Synology DS220
Easy setup and intuitive DSM software
Synology DS220
Easy setup and intuitive DSM software
2Mid
Ugreen DH4300
Easy setup for beginners
Ugreen DH4300
Easy setup for beginners
3Mid
Synology DS920
Long-term reliabilityNetworking speed beyond 1GbpsPlex and media handling improved by SSD cacheFan noiseCPU thermal and virtualization limitsMixed value of RAM/SSD upgrades for basic use
Synology DS920
Long-term reliability
Networking speed beyond 1Gbps
Plex and media handling improved by SSD cache
Fan noise
CPU thermal and virtualization limits
Mixed value of RAM/SSD upgrades for basic use
4Premium
Synology DS1821
Expandable storage capacityReliability and data recoveryEase of use / DSM interfaceDrive compatibility alerts and vendor lock-inWeak Plex transcodingExpensive proprietary RAM
Synology DS1821
Expandable storage capacity
Reliability and data recovery
Ease of use / DSM interface
Drive compatibility alerts and vendor lock-in
Weak Plex transcoding
Expensive proprietary RAM
5
OWC Mercury Elite Pro Dual
Bus-Powered FlexibilityCompact, Portable DesignDrives Readable If Enclosure FailsNoisy Drive ActivityAbrupt Unmount SoundRAID 1 Doesn't Boost Read Speed
OWC Mercury Elite Pro Dual
Bus-Powered Flexibility
Compact, Portable Design
Drives Readable If Enclosure Fails
Noisy Drive Activity
Abrupt Unmount Sound
RAID 1 Doesn't Boost Read Speed
Best value
6Budget
Synology DS118
Sufficient for backups, streaming, and surveillanceEasy setup for beginnersGood value versus higher-tier modelsNo drive redundancyConfusing entry-level lineup overlapMissing vibration dampers
Synology DS118
Sufficient for backups, streaming, and surveillance
Easy setup for beginners
Good value versus higher-tier models
No drive redundancy
Confusing entry-level lineup overlap
Missing vibration dampers
7Mid
Synology DS923
Great for Time Machine and photo backupLong-term reliabilitySolid upgrade from older/competing NASRAID is not a backupDrive/component lock-in and costNoise and power draw
Synology DS923
Great for Time Machine and photo backup
Long-term reliability
Solid upgrade from older/competing NAS
RAID is not a backup
Drive/component lock-in and cost
Noise and power draw
8Mid
Ugreen DXP6800 Pro
Dual 10GbE and Thunderbolt connectivityStrong hardware for the priceExpandable and third-party OS friendlySoftware stability issuesFan noise at idleNVMe/PCIe lane limitations
Ugreen DXP6800 Pro
Dual 10GbE and Thunderbolt connectivity
Strong hardware for the price
Expandable and third-party OS friendly
Software stability issues
Fan noise at idle
NVMe/PCIe lane limitations
9Premium
Ugreen DXP6800
Flexible RAID and third-party OS supportStrong hardware specs vs competitorsCapable for video editing workflowsInconsistent idle fan noiseUGOS software immaturityReal-world transfer speed issues
Ugreen DXP6800
Flexible RAID and third-party OS support
Strong hardware specs vs competitors
Capable for video editing workflows
Inconsistent idle fan noise
UGOS software immaturity
Real-world transfer speed issues
You are here
10Premium
Synology DS1621+
Highly expandable hardwareHigh throughput with 10GbE and cacheStrong VM and app supportNo hardware transcoding for 4KConfusing cache setup guidanceConsumer NVMe cache reliability risk
Synology DS1621+
Highly expandable hardware
High throughput with 10GbE and cache
Strong VM and app support
No hardware transcoding for 4K
Confusing cache setup guidance
Consumer NVMe cache reliability risk

Who wins on what

Ranked by what users actually praise

Overall Impression

Expandability is the DS1621+'s biggest strength. Owners consistently upgrade RAM to 24-32GB, add NVMe cache drives, and install 10GbE or even 40GbE network cards to unlock much higher throughput. Users report speeds ranging from 400MB/s with all four 1G ports bonded up to 1000-3000MB/s with 10G or 25G cards and NVMe caching. It also comfortably runs multiple VMs, Synology Drive sync, and PostgreSQL databases, making it a versatile platform beyond simple file storage for home labs and small businesses.

NVMe caching requires care and proper hardware. Several commenters warn strongly against using consumer-grade NVMe SSDs as cache, since they aren't rated for that workload and can fail prematurely, risking volume degradation and data loss. Others report compatibility headaches, such as M.2 modules being physically too tall for the slot, and confusion over read-only versus read/write cache configurations. Some also report disappointing real-world transfer speeds despite fast SSD caches, suggesting setup and drive selection strongly affect results.

Media streaming exposes the NAS's hardware limits. Multiple users cite the absence of GPU-based hardware transcoding as a major drawback for Plex, especially with 4K HDR content, often requiring a separate Intel NUC to offload transcoding. One user resolved constant buffering by disabling hardware-accelerated encoding entirely. Others note the dated Ryzen CPU, 1Gb NICs by default, RAM locked at 2400MHz, and loud fans in quiet mode, though fan noise was fixed by swapping in aftermarket Noctua units.

Outdated / Not-accurate data?