How much RAM does a NAS need?
By Ryan Fournier · Reviewed by Claire Bergeron · Updated For a prebuilt NAS that stores files and runs backups, the factory RAM is almost always enough — 2 to 8 GB covers it. Add memory when you run containers or virtual machines, where each wants its own. For TrueNAS/ZFS, ignore the old '1 GB per TB' rule: ZFS sizes its cache to your active data, so a 100 TB file pool runs on 32–64 GB, not 128. Size it precisely with the TrueNAS RAM calculator.
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The verdict: which should you buy?
File storage barely needs more
A NAS serving SMB shares and pulling nightly backups is not memory-bound. The factory RAM in a Synology, UGREEN or QNAP handles that with room to spare, and adding more brings no noticeable gain for pure file work. If files and backups are all you do, spend the money on drives, not RAM.
Containers and VMs are what use RAM
The picture changes with Docker containers and virtual machines: each reserves its own memory, and a handful can exhaust 4–8 GB quickly. If you run Plex plus a stack of *arr apps, Home Assistant, a database, or a VM or two, that is when more RAM earns its place. Note the platform limits — an N100 or many entry NAS units cap at 16 GB, which is plenty for containers but rules out heavy virtualization.
The ZFS rule is a myth at scale
For TrueNAS the '8 GB plus 1 GB per TB' rule dates from the FreeNAS era and over-provisions badly on large pools — it would demand 128 GB for 120 TB, where 32–64 GB is comfortable in practice, because OpenZFS sizes its ARC cache to your active data, not the raw pool. The exceptions are deduplication (about 5 GB per TB of dedup data — rarely worth it at home) and many VMs. Work your exact case with the TrueNAS RAM calculator.
Buying in Canada
Canadians cross-shop Amazon.ca, Best Buy Canada, Canada Computers, Newegg.ca and Memory Express; the cheapest SKU moves between them, and we track Amazon.ca live in CAD as the baseline. It is worth a two-minute check across those before you buy a drive or a NAS.
On importing from Amazon.com: it rarely beats a local CAD price once you add exchange, any duty, brokerage and the harder path to a warranty claim or return. The exchange rate is not a penalty — the honest point is total landed cost plus how much easier a return or RMA is when you bought it in Canada. For a drive that will run 24/7 for years, local warranty support is worth real money.
NAS memory on Amazon.ca (CAD)
SO-DIMM and ECC modules in stock on Amazon.ca. Match your NAS's exact memory type before buying.
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Frequently asked questions
How much RAM does a NAS need?
For file storage and backups, the factory amount (2–8 GB) is almost always enough. Add RAM for containers and VMs, which each want their own. For TrueNAS/ZFS, size to active data, not the old 1 GB-per-TB rule — 32–64 GB suits even a 100 TB file pool.
Is 8 GB enough for a NAS?
For files, backups and a few light containers, yes. It gets tight once you run several containers or a VM. Many entry NAS units and the N100 cap at 16 GB, which covers most home use.
Does TrueNAS really need 1 GB of RAM per TB?
No — that rule is outdated. OpenZFS sizes its cache dynamically to your active data, so a 100 TB file pool runs on 32–64 GB. Only deduplication or many VMs push it higher. Use the TrueNAS RAM calculator.
Ryan Fournier covers home-server hardware and efficiency at nasdrives.ca: the right power supply, the UPS, and what a NAS actually draws running around the clock, priced against Canadian hydro rates.
Reviewed by Claire Bergeron, Editor-in-chief