How do NVRs record video feeds (And Best HDDs for NVRs and NAS)

  • Most people put great emphasis on getting the best cameras with the highest resolution in the market when building a video surveillance system
  • While being a sound approach, having an equally good Hard Drives for your NVR to store your feeds would be equally important
  • HDD designed for NVR and NAS ensure low failure rate and at the right capacity will save a lot of frustration and also be a pragmatic solution.
  • In this post, we will review how NVRs record video feeds, look at key factors you need to consider when choosing a hard drive and our recommendation on the best hard drives for NVRs
  • Also read: What is NVR (and 3 Best NVRs)

How Does NVR Record Video Feeds?

When someone mentions an NVR, you might think of a black box with blinking LEDs and camera ports. Although this is mainly correct, it oversimplifies things. An NVR is not a single mechanical device. It has an embedded operating system and a storage device. Since NVRs lack video capture cards, only the IP cameras have the capability to capture footage.

Video encoding and processing happen at the camera. Thereafter, the video is available to the recorder for remote access and storage purposes. Some NVRs (Like Reolink NVRs) would have HDDs already included in the devices, for the majority of other NVRs (like Amcrest NVRs) you would need to find a good HDD to install.

Why Do You Need Special Hard Drives For NVRs And NAS?

  1. High intensity of use: A common practice is that you would store up to one month of recording. After that the new month of the recording will be recorded on top of the existing feeds, replacing the files. Compared to desktop computers, you will have much higher times of writing on the file.
  2. Backup Strategy: Multiple people can access files on it whether locally or remotely. With a NAS NVR setup, you use the NAS as the primary storage device. Since it has a RAID (Redundant Array of Independent Disks) setup, one of the other disks is for backup.
  3. Constant Use: By nature of the camera feed recording, you will be more or less constantly writing on the HDD which increase the risk of failure.   

Can you use a desktop-grade HDD for NVR or NAS?

Although you can use a desktop-class hard drives with your network video recorder, we do not recommend it. It might be cheaper at the beginning, but it will cost you more in the long run because of more intense read/write cycle needed win CCTV recording systems and home servers.

I’m sure you have probably thought about that as a cost-effective option already. It would be, if only it worked that way. In essence, there is a difference in how a “normal” hard drive functions and how a video optimized and NAS HDD operates.

What is special about Hard Drives for NVR?

The HDD you use in a Network Video Recorder has the capability to record videos, sounds and images from multiple sources and channels. Since it is required to be active 24/7, a surveillance hard drive has higher reliability and faster writing speed than a desktop HDD.

Such recorder hard disks have firmware that makes data recovery possible in case of drive failure, interference or damage. A video optimized HDD has the technology to cool faster than a normal hard drive, considering it will be running for long hours.

What is special about Hard Drives for NAS?

Any Network Attached Server runs continuously and produces less heat than a normal desktop drive. This is a result of its vibration sensors and the ability to cool faster even with multiple disks in operation.

With better performance and durability, you can use this device for a long time without failure. When compared to desktop HDDs, NAS has lower power consumption and produces less noise.

How to choose Hard Drives for AN NVR and NAS?

Getting an HDD for your NVR depends on your storage requirements. As mentioned earlier, you can go for a dedicated NVR or Network Attached Server.

Each option offers different capabilities.

If you are thinking of getting a NAS NVR setup, keep in mind the following factors:

  • To view the surveillance videos on your TV, the model of NAS you buy should have UPnP/DLNA. With such standards, you can be able to transfer recorded footage to a media player.
  • To manage recorded videos from different cameras within the same network, get one that supports IP surveillance.

Now, with that covered, let us get to the key deciding factors that determine the HDD you get for your recorder.

4 Important Factors to whey buying a Hard Drive for Your Network Video Recorder or NAS

  • Put reliability first: It is important to buy an HDD from a trusted brand. Reputable brands put in the money and effort into research and development to ensure their devices function properly with necessary warranties. Check the ratings indicated on the device and compare it to other brands. Most companies will list transfer rates and include the MTBF (Mean Time Between Failure). Always choose one with a higher MTBF. One of the ways to do it is to read the Hard Drive Stats by some storage companies , like the Q1 19 Report from Backblaze
  • Look for specialized hard drive series: Manufacturers will indicate the key features that make their devices the best in the market. Look out for terms like quiet, low heat, advanced power management, vibration tolerance and cooling technology. It is also recommended to buy special lines of HDDs that are designed for servers. This will ensure that the design and operating characteristics are suitable for using in NVRs and NAS.
  • Think about the power efficiency: It might seem like a trivial factor to consider when choosing an HDD for your NVR. However, power consumption is a serious issue that can increase the cost of running your surveillance system.
  • Understand the storage capacity needed: The capacity of the HDD you use in your recorder should accommodate your needs.  At any point, always go for larger storage than a smaller one.
    • If it is for a business premise, keep in mind your future plans and account for that as well. You may be using the typical 1080p resolution right now, but 4K will soon become synonymous with video surveillance.  
    • With 4K, 500GD HDD will no longer be enough. So, instead of getting 500GB now, go for anything beyond 1TB.  If you will use a NAS NVR setup, there is the advantage of RAID. You can use multiple disks with different storage capacities. The disks capacity range from 1TB to 14TB.  For a RAID setup, it is advisable to have disks with the same capacity.
    • If for example, disk 1 is 2TB and disk 2 is 4TB, then ultimately you limit disk 2 to 2TB only.

How much storage do I need for my NVR?

The storage capacity you need in your recorder depends on a few common factors such as:

  • Number of frames per second: The frame rate of a camera is the number of images the camera can capture in a second. A higher frame rate makes for a smooth video with better clarity. Most systems work at 30fps. At a higher frame rate of 60fps, you get a clearer video but with more storage and bandwidth requirements.
  • Motion detection: Since motion recording does not capture stationary objects, you can schedule it for a couple of hours a day depending on your environment.
  • For outdoor parking, motion detection can be set to run for longer hours compared to your home backyard.
  • Video Compression: This reduces the size of the video by getting rid of unwanted files by using a codec. Most IP cameras have a codec that enables you to store more footage in your HDD. The most common compression formats include MJPEG (Motion JPEG), MJPEG4 and the latest, H.265.
  • Resolution: To simplify, the more pixels an image has, the better the clarity and detail it has. The higher the details on an image, the higher the resolution. If you have an image in two different resolutions, the one with a higher resolution is bigger in size than the one with a lower resolution.  Therefore, a 4K image will require more storage than a Full HD image.
  • Number Of Cameras: The more cameras you have in your system, the higher your storage requirements. To help you understand how storage allocation works, we will use a simple setup for illustration. The number of cameras will vary. Other parameters will remain the same.

What Hard Drive size do I need for my NVR and NAS?

See the table below with the amount of storage you need at

Number of cameras   1 2 3
Continuous Recording (24 Hours)   Yes Yes Yes
Motion detectionQuite Area
(2 Hours per day)
Crowded Area
(4 Hours per day)
Quite Area
(2 Hours per day)
Video compression   H.265- 10 (High quality) H.265- 10 (High quality) H.265- 10 (High quality)
Frame rate per Second (fps)   30 30 30
Number of days of stored footage 7 Days 7 Days1 Month
Resolution   1920 x 1080p 1920 x 1080p 1280×720 px
HDD Capacity   100 GB 400 GB 200 GB

Best HDD for NVR

For a dedicated NVR setting, you need a reliable surveillance HDD. Based on market research and customer reviews, you cannot go wrong with either of these options below:

  • Seagate SurveillanceSeagate SkyHawk 8TB ($199.00) – This is an incredible surveillance drive from a reputable company. It works for both NVRs and DVRs. You can get it in a variety of sizes depending on the needs of your surveillance system.
  • Western Digital PurpleWD Purple 8TB ($234.92) – It provides compatibility with multiple NVR brands. The drive comes with a capacity selector that helps you determine the storage you require for the number of cameras you have.

Below is a side-by-side comparison of the two brands.

Features Seagate SkyHawk WD Purple
Price $199.00 $234.92
Application Perfect for High Definition Cameras Perfect for small businesses or home use.
Camera support Supports up to 64 HD cameras Supports up to 64 HD cameras
Capacity 1,2, 3, 4, 6, 8 TB 500GB, 1, 2, 3, 4, 6, 8, 12 TB
Form Factor 3.5 Inch 3.5 Inch
Disk Speed Not disclosed 5400 rpm / 7200 rpm
Interface SATA 6GB/s SATA 6GB/s
Workload 180 TB/year 180 TB/year
MTBF 1 million hours 1.5 million hours
Warranty 3 Years 3 Years

Best HDD for NAS

When buying a NAS you can go either for one with a hard drive enclosure or one with pre-installed storage. For one with an enclosure, you have to determine the number of internal bays. These are the open spaces where you can connect an HDD. To simplify, the more bays a device has the more storage you can enjoy. Devices with multiple bays provide RAID redundancy that guarantees data recovery.

Now, when buying a NAS HDD with an enclosure, take note of the number of revolutions per minute (rpm) and name of the manufacturer. The rpm figure on a HDD indicates the speed of the drive. In terms of manufacturer reliability, Toshiba, Seagate and Western Digital are the popular brands in the market.

With that said, the following breakdown below will help you get a clear picture of which device you need for your video surveillance.

Features Toshiba N300 Seagate Iron Wolf Seagate Iron Wolf PRO WD RED
Form factor 3.5 Inch 3.5 Inch 3.5 Inch 3.5 Inch
Capacity 4, 6, 8, 10, 12, 14 TB 1, 2, 3, 4, 6, 8, 10, 12, 14 TB 2, 3, 4, 6, 8, 10, 12, 14 TB 1, 2, 3, 4, 5, 6, 8, 10 TB
Number of Internal Bays 1-8 bays 1-8 bays 1-24 bays 1-8 bays
Interface SATA 6GB/s SATA 6GB/s SATA 6GB/s SATA 6GB/s
Disk Speed 7200rpm 7200rpm 7200rpm 5400rpm
Cache 128MB, 256MB 256MB 256MB 64MB, 128MB, 256MB
MTBF 1 million hours 1 million hours 1.2 million hours 1 million hours
Warranty 3 Years 3 Years 5 years 3 Years


It is no surprise that most people get the wrong drive for their Surveillance system. In the case that they do get the right one, it usually ends up being a frustrating task.

I hope this post will save you the mental stress and hours of research involved. Now, you can pinpoint the best HDD for your NVR that suits your Security System.

Whether you are going for a dedicated NVR or NAS NVR (where you use your NAS as the primary storage), you can find the appropriate drive that delivers on almost all of its marketing promises.

As always, make sure you check for compatibility before you buy any device. If you are getting a surveillance HDD to make sure it is compatible with the brand of recorder you have.

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Last update on 2024-07-12 / Affiliate links / Images from Amazon Product Advertising API

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