Sizing a Surveillance Hard Drive for High-Resolution Security Footage

Swap a handful of 1080p cameras for 4K units and the same NVR that ran comfortably for a month suddenly fills in a week. Resolution is the single biggest lever in sizing a surveillance hard drive, because a 4K feed can use around ten times the storage of an equivalent 1080p feed over the same recording period. Get the resolution mix wrong at the planning stage and no amount of clever settings recovers the lost retention afterwards.

Quick Answer

The 24TB Seagate SkyHawk AI, priced at R19,499, gives real headroom for mixed camera arrays because it supports up to 64 HD streams and 32 AI analytics streams on a single drive. Sites running mostly 1080p cameras with a handful of higher-resolution units at key entrances tend to get the best balance of retention and coverage from this capacity.

📐 Why Resolution Dominates the Sizing Decision

Frame rate and bitrate settings matter, but resolution sets the baseline that everything else scales from. A camera capturing fine detail at higher resolution generates meaningfully more data per second than a standard-definition equivalent, and across dozens of cameras running continuously, that difference compounds fast.

Planning a Mixed-Resolution Array

Most real installations are not uniform. Entrances, tills and high-value areas often justify higher resolution, while corridors, parking areas and general perimeter coverage can run at lower resolution without losing anything useful. Sizing your storage around this realistic mix, rather than assuming every camera runs at maximum resolution, gives a far more accurate picture of what a single 24TB drive can actually deliver.

🎥 Matching Stream Count to Camera Mix

With capacity for 64 HD streams alongside 32 AI streams, this drive comfortably covers a mid-to-large installation without needing multiple drives or a RAID array purely to hit the required channel count. Reserve the AI analytics allocation for cameras where motion detection or object recognition genuinely adds value, since AI streams tend to carry more overhead per channel than a straightforward HD feed.

Smaller sites with fewer than 64 total cameras get proportionally more retention headroom on the same drive, since fewer channels are drawing from the same 24TB pool.

Sizing for Future Camera Additions

A site rarely stays at the exact same camera count it started with. Leaving some of the 64-stream allocation unused at installation gives room to add a handful of cameras later without immediately needing a second drive or a full storage redesign. Planning this headroom in from the start is far simpler than retrofitting it once the site is already at capacity.

⚖ Balancing Quality Against Retention Requirements

If your compliance or operational requirements demand a minimum retention window, work backwards from that figure. Decide how many days of footage you legally or practically need to keep, then adjust resolution and bitrate on lower-priority cameras until the maths fits comfortably within the drive's 24TB capacity. This drive's 550TB per year workload rating means you have room to run higher bitrates than a standard desktop drive would tolerate, without the drive itself becoming the limiting factor.

Its 2.5 million hour MTBF also matters here, since a sizing plan that assumes years of continuous high-bitrate recording needs a drive built to survive that duration of sustained duty.

🔩 Fitting the Drive Into Your Existing Setup

Physically, this is a standard SATA 6Gb/s drive, so sizing decisions rarely need to account for exotic interface requirements. The bigger planning question is whether your NVR chassis and licensing support the channel count you are aiming for, since the drive itself can already handle up to 64 HD plus 32 AI streams. Check the internal hard drives section if you are also comparing bay-count and cache differences across similar capacity drives before finalising your build.

For teams speccing multiple sites with different resolution needs, it helps to look across Evetech's storage drive range rather than assuming one capacity fits every location, and this 24TB SkyHawk AI drive remains the reference point for sites running a genuinely high channel count.

Frequently Asked Questions

How much more storage does 4K use compared to 1080p?

A 4K feed can use roughly ten times the storage of a comparable 1080p feed recorded over the same period, though exact figures vary with compression and frame rate.

Should every camera in an installation use the same resolution?

Not necessarily. Matching resolution to what each camera actually needs to capture, rather than defaulting to the highest setting everywhere, usually gives better real-world retention.

Does this drive support a mix of resolutions across its 64 streams?

Yes, the 64 HD and 32 AI stream capacity accommodates a mixed-resolution camera array rather than requiring uniform settings across every channel.

What happens if I size the drive too small for my camera mix?

Retention time shortens, and most NVR software will begin overwriting the oldest footage sooner than planned once capacity fills.

Is one 24TB drive enough for a full commercial site?

For many mid-sized sites, yes, particularly when higher-resolution cameras are reserved for a handful of priority locations rather than applied uniformly.

Does adding AI analytics streams reduce the HD capacity available?

The 64 HD and 32 AI stream figures are separate allocations on this drive, so planning both into your sizing calculation from the outset avoids surprises once analytics cameras go live.

Should sizing account for future camera additions?

Yes, leaving some headroom in your initial channel count makes it far easier to add cameras later without a full storage redesign.