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You've answered a few questions for me about my old DS1813+ and potentially moving to a Mac mini for Plex server. My thought now is to get a DS 1821+ (to avoid the drive issue), move my existing drives into that and add a 10GbE card and possibly additiona RAM.
This more expensive but hopefully preserves my investment in drives that are SHR-2.
What 10GbE card does the DS1821+ use? I can't seem to find an authritative answer.
What would you suggest for additional RAM? While I have my wallet open how much would you put into this?
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Great questions—and you're on a smart path. The DS1821+ is a solid upgrade from the DS1813+ while preserving your investment in drives and SHR-2. Here’s what you need to know:
1. 10GbE Card Compatibility for DS1821+
The Synology DS1821+ uses a PCIe Gen3 x8 slot, and it supports Synology’s own E10G21-F2 10GbE SFP+ card (dual port) as the officially supported option.
✅ Officially Supported:
Synology E10G21-F2 (dual SFP+)
Synology E10G18-T1 (single RJ45 10Gbase-T)
Synology E10G18-T2 (dual RJ45 10Gbase-T)
? Unofficial/3rd-Party Options (may work but not guaranteed):
Intel X520-DA2 (SFP+)
Mellanox ConnectX-3
Chelsio T520 series
These work for many users, especially with DSM 7.x, but driver compatibility is not always guaranteed and may break with updates.
If you want plug-and-play reliability, stick with Synology’s official cards. If you're comfortable troubleshooting and want to save money, Intel or Mellanox cards can be a good alternative.
2. Additional RAM for DS1821+
Base RAM: 4 GB DDR4 ECC SO-DIMM (non-removable)
Expansion Slot: 1 additional SO-DIMM slot
Max Supported (Officially): 32 GB (16 GB + 16 GB)
Unofficially Confirmed: 32 GB total (i.e., add 1×16 GB ECC DDR4 SO-DIMM)
? Recommended RAM:
Crucial CT16G4SFD8266 – 16GB DDR4 2666 ECC SO-DIMM (commonly used by Synology users)
Synology D4ES01-16G – Synology's official module, more expensive but guaranteed compatible
? How much to add?
16 GB total (add 1×8 GB) is usually enough for Plex, file sharing, Docker, and light VMs.
20 GB total (add 1×16 GB) is a sweet spot if you’ll run heavier workloads (e.g. multiple Docker containers, VMs, heavy Plex metadata, hardware transcoding via Mac Mini frontend).
32 GB total if you're going all-in and want maximum headroom for future-proofing.
✅ Your Setup Plan Sounds Great
Reuse SHR-2 drives in a newer, faster platform
Gain 10GbE for faster LAN access
Optionally move Plex to a Mac mini for better transcoding (as DS1821+ lacks an iGPU)
