Is it worth upgrading NAS memory? Comparing the 4GB/8GB/16GB levels, I've tried both Feiniu and Synology

many people ask "Do you want to add more RAM" when they buy a NAS? But Feiniu and Synology come with 4GB or 8GB by default at the factory, which seems sufficient. Once I actually started using it, I found that opening three or four Dockers at once caused web backend lag for ages, and my phone's photo album syncing got stuck as a PowerPoint.

my Feiniu N100 mini PC at home has been upgraded from 4GB to 16GB for over half a year. Every upgrade I tested in real-world scenarios. Today, I'll present the comparison data—just follow your example.

clarify first: what exactly does NAS memory have

many people think NAS is for storing files, so it doesn't matter if the memory is larger or smaller. This is fine for pure idle download drives, but if you run Docker, transcode, or have several people accessing it at once, memory is the lifeline.

specific impacts are these

• web backend response : Both Synology DSM and Feiniu fnOS use Linux+Web architecture, and with 4GB of memory, opening the "Control Panel" takes three seconds to spin.
• Docker : Each container starts with at least 200MB of resident memory. On a 4GB machine, running Jellyfin + qbittorrent + Immich at the same time basically causes an explosion.
• transcoding performance : Feiniu Album's AI facial recognition and Jellyfin's real-time transcoding are both memory consumers. If memory is insufficient, swap directly; mechanical disk swapping might make you think the NAS is broken.
• multiple devices concurrently: When three family members watch movies on the NAS simultaneously, 4GB of memory is fully consumed by SMB cache, creating a buffer ring.

4GB test: Enough, but don't be greedy

the original 4GB version, I only dare to open two lightweight services: qbittorrent download + Syncthing sync. Keep the number of Dockers under 3.

measured data:

• Free memory: ~1.2GB
• qbittorrent Tasks: Occupied ~280MB
• Syncthing Synced 5000 photos: Occupied ~180MB
• Web backend response: opens control panel in 3-5 seconds, occasionally 10 seconds +

can hold up, but the experience is really unpleasant. Once, I ran Feiniu album scraping + Jellyfin transcoding at the same time, and the memory was reduced to just 200MB. The fnOS web backend was completely unresponsive, and only restored after a hard reboot.

4GB Who is it suitable for: pure downloadable disks, only PT setups, only you at home, no Docker, no transcoding.

8GB Test: 90% of family users have dessert

upgrading to 8GB is, in my opinion, the best value tier. The Feiniu N100 mini PC comes with a single 8GB stick; I switched to dual-channel (not very practical but psychologically comforting).

measured data:

• Free memory: ~5GB
• running Jellyfin + qbittorrent + Immich + Feiniu album + Syncthing: Usage ~2.8GB
• webpage backend response: 1-2 seconds, occasionally instantly opening
• 3 people to view 4K original discs: Jellyfin transcoding at 1080p with no pressure

keeping the daily number of Dockers under 6-8 is basically imperceptible. I opened 5 core containers at the same time, and the backend still had free space.

8GB Who is it suitable for 2-3 devices at home, running 3-5 Dockers, and not doing extensive AI scraping and transcoding. This is the real need of the vast majority of family users.

16GB Test: The End of Enthusiasts, But Don't Randomly Upgrade

upgraded to 16GB because I was reckless and added it, but most of the time I found it was never fully used. The N100 only has one SO-DIMM slot; I used a Lenovo disassembled 16GB DDR5 5600 slot.

measured data:

• Free Memory: ~13GB (mostly idle and gathering dust)
• running Jellyfin + qbittorrent + Immich + Feiniu Album + Syncthing + HomeAssistant + Vaultwarden + Calibre-Web: occupying ~4.2GB
• Webpage backend response: Always open instantly
• AI face recognition scrapes 10,000 photos: memory peak 6.8GB, drops back to 4.5GB
after running

looks great, right? But the price is:

• 16GB DDR5 SO-DIMM sticks still cost over 300 yuan each, which is quite high on a 1500-yuan small PC. Idle memory
• ≈ wastes power. Although DDR5 is low-voltage, the monthly power difference between 8GB and 16GB is less than 2 kWh when running long-term
• The biggest drawback: Feiniu fnOS is less optimized than 16GB RAM compared to Synology. Under Synology DSM, 16GB can really be used up to 80%, but many Feiniu services still stick to the default configuration mindset

16GB Who is suitable for: NAS running 10+ Docker simultaneously, AI training/inference, extensive video transcoding, and having more than 4 family members online simultaneously. Scenes like this are actually quite rare.

Pitfalls in Choosing Memory: Don't Buy Recklessly

The biggest pitfall with

Liter of memory isn't the capacity, but compatibility. The Feiniu N100 uses laptop DDR5 SO-DIMM, while the Synology DS224+ uses DDR4 ECC SODIMM—the two are completely mismatched.

a few must-see points:

I once bought a "generic DDR5 16GB" stick for a cheap price. Finiu fnOS recognized it on boot, but after running Docker for three hours, it randomly showed a blue screen (fnOS blue screen means the network is disconnected but the fan is still running). Later, I switched to a Lenovo disassembled device and it became safe. The lesson is: memory modules, which are long-term fully loaded components, don't save 100 yuan.

should you upgrade or not? My criteria

have reviewed the three levels above, you should be able to judge accordingly. Simple and straightforward judgment:

1. is lagging right now: Upgrade directly, don't hold back—4GB → 8GB offer the biggest experience
2. Want to add Docker but haven't added yet: Upgrade to 8GB first, then Docker, or you'll regret it
3. Already 8GB and no lag: Don't upgrade, 8GB is a dessert spot
4. already 16GB and not fully used : Congratulations, you have too much money to spend

Another situation is for Synology users: DSM has slightly higher memory requirements than Feiniu because Synology Photos' facial recognition and Synology Office consume a lot of memory. If you use Synology for home office + photo albums, start directly at 16GB to save you the hassle of fussing later.

upgrade process is actually quite simple

steps can be explained in 5 minutes:

• turn off the device, unplug the power, wait 30 seconds for the capacitor to discharge
• open the small NAS cover (Feiniu N100 has 4 screws, Synology DS224+ has 2 paddles
• ), plug in the original memory at a 45-degree angle, hear a click
• cover back on
• System Backend → System Information → Memory Column Confirm Recognition of Full Capacity

note: dual channels must have two cables of the same capacity and frequency; single channels can work, but their performance is slightly inferior. The Feiniu N100 only has one slot, so there's no choice.

final advice: Before upgrading memory, first check how much your NAS motherboard actually supports. The Synology DS224+ officially claims up to 8GB, but community tests show 16GB is sufficient; The official Feiniu N100 has 16GB, but in actual tests, 32GB is acceptable. These are all folk games; to maintain stability, it's best to follow official specifications.

memory doesn't feel immediately after adding it, but when it's missing, it keeps making you feel awkward. Follow my criteria above, don't waste money.