The Synology DiskStation DS420j is a 4-bay NAS designed for home use. It comes with 1GB DDR4 of RAM (not user-upgradeable). Powered by the Realtek RTD1296 processor, it offers reliable network-attached storage for file sharing, backups, and media streaming.
This guide covers complete RAM and storage compatibility for the Synology DiskStation DS420j, including upgrade options, maximum supported configurations, and recommended drives.
Specifications Overview
| Specification | Details |
|---|---|
| NAS Model | Synology DiskStation DS420j |
| Brand | Synology |
| Drive Bays | 4 bays |
| Processor | Realtek RTD1296 |
| Default RAM | 1GB DDR4 |
| Maximum RAM | 1GB DDR4 |
| RAM Type | DDR4 |
| RAM Slots | 0 |
| RAM Upgradeable | No |
| M.2 Slots | None |
| Ethernet | 1x 1GbE |
| USB Ports | 2x USB 3.0 |
| Use Case | Home |
| Price Tier | Budget |
Memory (RAM) Compatibility
The Synology DiskStation DS420j comes with 1GB DDR4 which is not user-upgradeable. The RAM is soldered to the motherboard.
Storage Compatibility

The Synology DiskStation DS420j has 4 drive bays supporting 3.5″ SATA HDDs and 2.5″ SATA SSDs.
Recommended NAS Hard Drives
| Drive | Capacity | Price |
|---|---|---|
| Seagate IronWolf | 4TB | Check Price |
| Seagate IronWolf | 8TB | Check Price |
| WD Red Plus | 4TB | Check Price |
| WD Red Plus | 8TB | Check Price |
Network Connectivity
The Synology DiskStation DS420j features 1x 1GbE Ethernet and 2x USB 3.0 connectivity.
Related Guides
Frequently Asked Questions
What is the maximum RAM for the Synology DiskStation DS420j?
The Synology DiskStation DS420j supports a maximum of 1GB DDR4. It ships with 1GB DDR4 by default.
How many drive bays does the Synology DiskStation DS420j have?
The Synology DiskStation DS420j has 4 drive bays supporting 3.5″ SATA HDDs and 2.5″ SATA SSDs.
Can I upgrade the RAM in the Synology DiskStation DS420j?
No, the RAM is soldered and cannot be upgraded.
What hard drives work with the Synology DiskStation DS420j?
The Synology DiskStation DS420j works with standard 3.5″ SATA HDDs. We recommend NAS-rated drives like the Seagate IronWolf or WD Red Plus.
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Prices from PCHub.UK via ComputersDeal. As an affiliate, we may earn from qualifying purchases. Prices updated 2026-04-10 13:15:58.

