Surveillance Drives in a NAS: What Actually Works

Data updated 2026-09-15

UniFi: a spec, not a list

Ubiquiti's own storage requirements article states the 3.5-inch bay requirement verbatim:

“1TB or larger CMR drive with 7200RPM read/write speeds. 5400RPM is not recommended for multi-bay consoles in RAID 5/6/10 or using ZFS.”

Source: UniFi Storage Requirements and Compatibility — https://help.ui.com/hc/en-us/articles/360037340954-UniFi-Storage-Requirements-and-Compatibility, read 2026-08-19.

Standard Seagate SkyHawk's commonly-cited 5900RPM is reseller-corroborated rather than Seagate-stated (Seagate's own simple datasheets do not print an RPM column for that line), so it is not counted as meeting the clause here. SkyHawk AI and WD Purple Pro both state 7200RPM on specific part numbers, which do clear it - see the live table below for exactly which rows.

Synology: a list with zero third-party 3.5-inch HDDs

This is not a per-drive spec check the way UniFi's is - it is a policy position that applies to every surveillance drive equally, because none of them appear on Synology's own list at all. On a 2025-and-later DS Plus or desktop FS machine, an unlisted HDD can still create a new storage pool, flagged Unverified in Storage Manager. On a Value or J-series machine, it cannot - not for a pool, a cache, or a migration. See the full sourced Synology policy rather than us re-deriving it here.

QNAP: annotated, not gated

QNAP publishes a genuinely different tested-drive list per machine and flags what it has not verified, but an unlisted drive still builds a volume. See the compatibility hub for QNAP's per-machine registry pages.

The practical difference between QNAP's posture and Synology's is worth stating plainly: QNAP's list is a recommendation surface, not a gate, so a surveillance drive absent from a specific QNAP model's tested list still functions normally. Synology's Value and J-series restriction is the opposite - a genuine functional block on new pool creation, not merely an unflagged recommendation. Two vendors using superficially similar "compatibility list" language can mean very different things for whether a drive actually works, which is exactly why this page treats them separately rather than collapsing both into one generic "compatibility" badge.

Why three vendors get three different treatments here

UniFi's posture is a specification: any drive, from any manufacturer, either measurably clears 1TB+/CMR/7200RPM or it does not, and that is a fact about the drive independent of who makes it. That is the only one of the three postures a per-drive computed table can honestly represent, because it is the only one that is actually a per-drive check.

Synology and QNAP's postures are facts about a MACHINE CLASS's policy toward unlisted drives in general, not about any specific surveillance drive's specification. Building a per-row "Synology: PASS/FAIL" column would imply a spec check that does not exist - Synology does not publish RPM or recording-technology thresholds for third-party drives the way UniFi does, it publishes a named list, and that list contains no surveillance drive from either manufacturer we track. Stating the policy once, plainly, is the honest representation; a computed badge per row would overstate what we actually know.

Every in-stock surveillance drive we track, against UniFi's spec

A row labelled unverified has no model_tech record confirming both recording technology and spindle speed for its exact part number - excluded from the "meets spec" count rather than assumed to pass.

Recording technology and spindle speed for this table come from model_tech, the same curated per-part-number registry the sitewide UniFi gate at /compatible/unifi-unas reads from - not from the drive listing's own title or a reseller's claim, which is why several capacities we otherwise track show as unverified here despite being in stock and priced live elsewhere on the site.

What "in stock" means for this table

Every row reflects a listing we track as currently purchasable - out-of-stock capacities and part numbers are excluded entirely rather than shown greyed out, so the population above changes as stock changes. A capacity that clears UniFi's spec today can drop out of this table tomorrow if its last listing sells out, and a newly-stocked capacity can appear the next time this page is requested.

How this table gets built

Every in-stock SkyHawk, SkyHawk AI, WD Purple and WD Purple Pro row we track is joined against model_tech by exact part number, the same prefix-matching join the sitewide UniFi gate uses. A row with no matching model_tech entry - because we have not independently sourced that exact part number's recording technology and RPM - renders unverified rather than being assumed to inherit its series' typical spec. This is computed fresh on every page load, not a static snapshot, so the counts above change as stock and sourcing change.

What this means if you're choosing a drive for a NAS specifically

If UniFi is your target platform, the table above is the actual answer: pick a row marked MEETS SPEC, or check the exact part number of anything else before buying it for that console. If Synology or QNAP is your target, the per-row UniFi result is largely beside the point - Synology's Unverified flag applies to every surveillance drive equally regardless of its RPM, and QNAP builds a volume from an unlisted drive regardless of its RPM too. In both of those cases, the decision that actually matters is whether you are on a machine class that restricts new pools at all (Synology Value/J-series) rather than which specific surveillance drive you pick.

Sources checked: UniFi Storage Requirements and Compatibility, Synology compatibility search, QNAP compatibility search.