Decision on HDD for CCTV

[BenStark]

Looking to replace the HDD in my CCTV NVR, and I know WD Purple is the one advisable for CCTV.

 

I currently have the choice between a new 4 TB WD purple, with 3 year Synnex warranty, for 2500 baht.

 

On the other hand, I found a second hand 10 TB WS Purple, with 3 year Synnex warranty left, for 4100 baht. The 10 TB version cost normally about 9K, and has 5 year warranty by default. Other versions have only 3 year by default

 

Which would be my best choice.

 

I tend to believe that a 10 TB disk will last longer than a smaller one, because of less overwriting during the same timespan, and an extra 1600 baht for 6 TB more is of course not a bad deal.

 

Which one you guys would go for

 

 

[KhunHeineken]

I prefer Seagate Skyhawk HDD's for my system.

 

I suggest you install two HDD's, if your system supports multiple HDD's, which most do these days.  The reason is, if one HDD fails, footage is still being recorded on the other HDD.  If money is tight, 2 x 2TB HDD's would not be much more than 1 x 4TB HDD, but you now have some redundancy.     

 

You might find the info that backblaze collect on HDD's interesting.  Backblaze publish reliability stats on HDD's. 

 

Here's an article from pcworld.

 

https://www.pcworld.com/article/1810214/back-it-up-most-dead-hard-drives-fail-within-3-years.html

 

Here's backblaze's HDD stats for Q2 2023. 

 

https://www.backblaze.com/blog/backblaze-drive-stats-for-q2-2023/

[Gottfrid]

As the above post recommend it will be better with two smaller HDD´s. If you are worried about too much overwriting, there is always a choice of SSD that will hold much longer time.

Edited December 14, 2023 by Gottfrid

[LS24]

1 hour ago, BenStark said:

Looking to replace the HDD in my CCTV NVR, and I know WD Purple is the one advisable for CCTV.

 

I currently have the choice between a new 4 TB WD purple, with 3 year Synnex warranty, for 2500 baht.

 

On the other hand, I found a second hand 10 TB WS Purple, with 3 year Synnex warranty left, for 4100 baht. The 10 TB version cost normally about 9K, and has 5 year warranty by default. Other versions have only 3 year by default

 

Which would be my best choice.

 

I tend to believe that a 10 TB disk will last longer than a smaller one, because of less overwriting during the same timespan, and an extra 1600 baht for 6 TB more is of course not a bad deal.

 

Which one you guys would go for

 

 

 

Ben, HDD tend to fail quickly if they are going to fail under normal operating conditions. What you may not know is the life that the second hand HDD has led. It could have been cooked in a case with little to no ventilation and cooling, or been repeatedly thrashed with read - writes. It could have been dropped. If I did happen to buy it I would give it a low level (as opposed to a standard flag change) format before putting it into use to check for bad sectors.

 

What is your CCTV camera recording format and how much data per hour dies it record on high quality? Is it running 24/7? How long do you need to keep footage for? Answer those questions and make a simple calculation then you have your answer to the size you need for your usage. Is the CCTV critical. Do you actually need redundancy?

HDD aren't as sophisticated as SSDs in where they share their location of storage usage so having a larger drive won't nessessarily share the wear. Main failure that I have found is on the read / write head or the arm actuators or their electronics, not on bad sectors on an HDD platter.

 

 

28 minutes ago, KhunHeineken said:

I prefer Seagate Skyhawk HDD's for my system.

 

https://www.pcworld.com/article/1810214/back-it-up-most-dead-hard-drives-fail-within-3-years.html

 

Here's backblaze's HDD stats for Q2 2023. 

 

https://www.backblaze.com/blog/backblaze-drive-stats-for-q2-2023/

I used to look at the Backblaze data when it was important for me to know that information. It isn't now. But back then Seagate had a much higher failure rate consistently and it seems that they still do now. What reason do you have for preferring Seagate Skyhawk HDD? Is there data to help you come to that conclusion or is it just a personal choice with no technical backing? Either is fine. It just helps others understand your reasoning.

Edited December 14, 2023 by LS24

[BenStark]

42 minutes ago, KhunHeineken said:

I prefer Seagate Skyhawk HDD's for my system.

 

I suggest you install two HDD's, if your system supports multiple HDD's, which most do these days.

 

My experience with Seagate HDD for PC is not good, and I did look at Backblaze, which confirms this.

 

Unfortunately my NVR allows only 1 HDD  Dahua XVR5108HS-I3

 

18 minutes ago, Gottfrid said:

If you are worried about too much overwriting, there is always a choice of SDD that will hold much longer time.

 

I do look at the CCTV forums, and SSD's are advised against, because they will wear out faster with constant writing.

 

If you want an enterprise or surveillance grade SSD, you will also pay a lot more over a HDD for the same storage space

 

26 minutes ago, LS24 said:

HDD tend to fail quickly if they are going to fail under normal operating conditions. What you may not know is the life that the second hand HDD has led. It could have been cooked in a case with little to no ventilation and cooling, or been repeatedly thrashed with read - writes. It could have been dropped. If I did happen to buy it I would give it a low level (as opposed to a standard flag change) format before putting it into use to check for bad sectors.

 

WD Purple are designed for surveillance (constant writing) and since the 10TB has still 3 year warranty left, I could only hope it fails :-) as I would get a new one from Synnex

 

I have 8 x 2MP cameras streaming at 30Fps. So if they record 24/7, I would need 4TB for 7 days storage before they start to overwrite. In principle that would be sufficient

 

With a 10TB that would last 18 days, so significantly less overwriting, so I thought that would be beneficial to the lifespan of the HDD. Also since 10TB has 5 year warranty from manufacturer, where the lower capacity versions have only 3, I would think it is a better quality HDD after all, and the price is not that much more

[KhunHeineken]

1 hour ago, LS24 said:

used to look at the Backblaze data when it was important for me to know that information. It isn't now. But back then Seagate had a much higher failure rate consistently and it seems that they still do now. What reason do you have for preferring Seagate Skyhawk HDD? Is there data to help you come to that conclusion or is it just a personal choice with no technical backing? Either is fine. It just helps others understand your reasoning.

 

Fair question. 

 

I buy the Seagate Skyhawk helium filled HDD's for my NVR.  They are not standard surveillance HDD's.  They are more commercial grade HDD's.  

 

If you look at Backblaze, yes, I agree, the Seagate is not the best, but it is better than Western Digital.  

 

Given I rotate and swap out the HDD's, I have never had a failure, but that probably more to do with good HDD management than Seagate HDD reliability.  Please note I said "prefer" not "recommend" so there is some personal choice in there, and price point value for money as well.   

[BenStark]

5 hours ago, KhunHeineken said:

If you look at Backblaze, yes, I agree, the Seagate is not the best, but it is better than Western Digital.  

 

Guess you need new glasses. From your own link, and FYI, HGST is owned by WD

5 hours ago, KhunHeineken said:

Given I rotate and swap out the HDD's, I have never had a failure, but that probably more to do with good HDD management than Seagate HDD reliability. 

 

You mean you replace them before they fail, or your drives last indefinitely because you rotate and swap them?

[KhunHeineken]

3 hours ago, BenStark said:

 

Guess you need new glasses. From your own link, and FYI, HGST is owned by WD

 

You mean you replace them before they fail, or your drives last indefinitely because you rotate and swap them?

I guess you need glasses, not me. 

 

I buy the 0008 model, which is helium, in 10TB.  I have three of them, so that's 30TB of storage, which is weeks.  I also subscribe to off site storage, in case someone wants to steal the NVR to destroy the evidence. 

 

Did you see the 0008 model with 1,763,868.  I guess you didn't, because you need glasses. 

 

There's a mix of price point V value for money.  Seagate Skyhawk has always been good value. but I have always practiced good HDD management. 

 

3 hours ago, BenStark said:

You mean you replace them before they fail, or your drives last indefinitely because you rotate and swap them?

Same Same. 

 

I replace one of them every year, which means the NVR always has a 1 year old HDD, should the other two fail simultaneously, which is highly unlikely.  At the time of the swap out, I dust out the board and fan, which should be done annually anyway. 

[BenStark]

7 minutes ago, KhunHeineken said:

Did you see the 0008 model with 1,763,868.  I guess you didn't, because you need glasses. 

 

Of course I see the 0008 model, it has a 3.25% AFR rate.

 

 

If you consider that good, you must be trolling

[KhunHeineken]

17 hours ago, BenStark said:

 

Of course I see the 0008 model, it has a 3.25% AFR rate.

 

 

If you consider that good, you must be trolling

Do you see the 19,677?  Care to comment on that? 

[BenStark]

1 hour ago, KhunHeineken said:

Do you see the 19,677?  Care to comment on that? 

 

Yes I see that number, and it is the amount of drives they have in their database, which means nothing at all. It is the time they have been in use and the FAILURE rate that is important, and which is 3.25% over 38 months average age

 

WD has drives in use for 30.6 months, which is 8 months less than your Seagate, and a failure rate of 0.77%

 

 

 

 

Edited December 15, 2023 by BenStark

[KhunHeineken]

19 hours ago, BenStark said:

 

Yes I see that number, and it is the amount of drives they have in their database, which means nothing at all. It is the time they have been in use and the FAILURE rate that is important, and which is 3.25% over 38 months average age

 

WD has drives in use for 30.6 months, which is 8 months less than your Seagate, and a failure rate of 0.77%

 

 

 

 

The Seagate in the chart is a 12TB HDD.  You are quoting WDC at 14TB and 16TB.  The more TB, the less the overwrites. 

 

Comparing to the WDC 14TB, the Seagate 10TB has 19,677 HDD's installed, that the third highest amount in the chart.  Geez, I wonder why this is? Could it be that they are decent drives?     Your WD 14TB only 8,432 HDD's installed.  Big difference. 

 

Your WDC 14TB only did 759,062 drive days.  The Seagate did 1,763,868.  That's a big difference. 

 

Weighing up all of the stats, and looking at the bigger picture, with your new glasses on, you will see the Seagate model I deploy is a decent HDD for the money.

 

HDD's eventually fail, no matter what brand.  You really need at least a 2 bay NVR / DVR for when whatever HDD you install fails.  The chance of both failing at the exact same time is slim, unless there is a big electricity surge or similar.