How long a security camera package's hard drive stores footage isn't determined by the package price, but by three numbers: hard drive capacity, number of cameras, and the bitrate the recorder records at. At NewTech there are four packages available from the Tiandy brand, ranging from 200 KD for four 4MP indoor cameras to 400 KD for eight 8MP cameras, all with a 4K-capable recorder and a surveillance hard drive. Notably, each package gives each camera roughly half a terabyte: four cameras with a 2 TB hard drive, and eight cameras with 4 TB. So retention doesn't get longer by moving from four cameras to eight, while moving from 4MP to 8MP shortens it because the sharper image takes up more space. In a calculation example at a bitrate of 2 Mbps per camera, retention approaches twenty days of continuous recording, and drops to about ten days if the bitrate doubles. The buying rule in Kuwait: make the retention days longer than your longest expected absence from home, such as summer travel, then choose the resolution.
How do I calculate the number of days the hard drive stores?
The calculation is simpler than it seems. Every megabit per second the recorder records over a full day takes up about 10.8 gigabytes, because a day has 86,400 seconds and a byte is eight bits. The whole formula comes from this, and you only need one number that you read from the recorder's own screen:
- Calculate the usable capacity: a 2 TB hard drive shows up in devices as about 1,800 gigabytes, and a 4 TB hard drive as about 3,600.
- Open the recording settings on the recorder and read the bitrate set for each camera in Mbps.
- Multiply the bitrate by 10.8 to find one camera's daily consumption in gigabytes.
- Multiply the result by the number of cameras to get the system's daily consumption.
- Divide the usable capacity by the daily consumption, and the result is the number of retention days with continuous recording.
How many days does each of the four packages store?
The table applies the formula to the available packages. The 2 and 4 megabit rates here are calculation examples, not a written specification of the cameras; the real number is what you read from your recorder's settings:
| Package | Price | Hard drive | Example at 2 Mbps | Example at 4 Mbps |
|---|---|---|---|---|
| 4 indoor 4MP cameras | 200 KD | 2 TB | About 20 days | About 10 days |
| 4 outdoor 8MP cameras | 220 KD | 2 TB | About 20 days | About 10 days |
| 8 cameras 4MP | 240 KD | 4 TB | About 20 days | About 10 days |
| 8 cameras 8MP | 400 KD | 4 TB | About 20 days | About 10 days |
The similar columns are no coincidence: the ratio of hard drive to number of cameras is constant across the four packages. What actually changes the result is the bitrate, and 8MP cameras usually need a higher bitrate to preserve their detail, so their result falls closer to the 4 Mbps example.
Why does 8MP resolution shorten retention?
An 8MP image has roughly twice the pixels of 4MP, and each frame needs more data to be saved without breaking up when zoomed in. This extra data is what lets you read a license plate or facial features at a reasonable distance, and it is also what fills the hard drive faster. So the right question before buying is: do you need distant detail in this specific spot? The living room, hallway and cashier usually don't need it, while the entrance, parking area and perimeter wall are the spots that justify 8MP.
How do I extend retention without changing the hard drive?
Three settings are worth trying from the recorder menu. The first is motion-triggered recording instead of continuous recording for cameras watching quiet areas, since a hallway no one walks through at night doesn't need hours of empty footage. The second is lowering the bitrate for nearby indoor cameras that don't need zooming. The third is checking that the overwrite-oldest option is enabled, so recording continues when the hard drive is full instead of stopping. After any change, redo the calculation with the steps above to find the new retention period.
Which package suits my place?
The 4MP indoor package is for apartments, offices, clinics and small shops, and the 8MP outdoor package is for anyone who needs to cover entrances and parking areas. The two eight-camera packages are for large homes, villas and warehouses, and the difference between them is resolution, not number. An important note from the product description: the recorder in the eight-camera packages has only four PoE ports, so the remaining four cameras need an additional PoE switch, which is decided during the site inspection with the technician, while the four-camera packages install directly without a switch. In Kuwait's summer, place the recorder in a ventilated spot away from the sun, because the hard drive runs around the clock. You'll find all the packages in the security camera packages collection, and the brand's products in the Tiandy collection.
Questions customers ask
What happens when the hard drive is full?
If the overwrite-oldest option is enabled, the recorder deletes the oldest recordings and continues. So copy any important clip as soon as you notice it, before it passes the retention period.
Is a regular computer hard drive enough instead of a surveillance hard drive?
It's not recommended. Tiandy packages come with a WD Purple hard drive designed for continuous writing, while a computer hard drive is designed for intermittent use and wears out faster under this load.
Can I add cameras later to the four-camera package?
The recorder in the four-camera packages has only four channels, so any fifth camera needs a larger recorder. If you expect to expand, start with the eight-camera package.
What is the delivery fee for the package within Kuwait?
Delivery within Kuwait is free for orders of 30 KD or more, and 1 KD for orders below that, and all four packages are above this threshold.
