WD Launches Purple Line of HDDs for Surveillance Market

Status
Not open for further replies.

RazberyBandit

Distinguished
Dec 25, 2008
2,303
0
19,960
Maybe because this sort of new product information can only be garnered from corporate press releases.I really didn't think there was a separate market for drives limited to "up to 32 input devices," since WD's Se-series drives could already handle up to 64 independent input devices. I guess market segmentation is never truly complete from a corporate standpoint.
 
Sep 22, 2013
482
0
10,810
The higher price usually has a lot more to do with data integrity than it does performance. The surveillance drives targeted for use with always-on cameras and audio recording need to perform consistently with little room for failure due to wear & tear; so they need to have quality moving parts, better tolerance on the manufacturing specs and survive for a higher number of read/writes more so than be fast.There have been a number of drive comparisons done by hard drive review sites on WD, Seagate and Toshiba which clearly show the performance in these drives is nothing extraordinary for day-to-day use; it's more about lifespan and data integrity. If a crime is caught on camera, it needs to be able to be accessed as needed without worry for a simple read-write error.
 

I don't think this is the right solution to that problem. I just put together a security camera system recently. The software supported initially writing the video files in one location, but archiving it in a different location. I so put a SSD and regular HDD in the system. The video received from the cameras is initially written to the SSD. After 3 days it gets archived (in batch) on the HDD.

1) You don't typically think of SSDs in this particular application - there's no need for blazing speed. But there is a need for constant concurrent writes to multiple files, which is something SSDs do a lot better than HDDs. I initially decided to go with the SSD because I noticed the computer frequently stuttered and lagged during competing read requests from the original HDD.

2) The HDD only gets written to about 4-6 times a day. At all other times, it goes to sleep. So I just grabbed a consumer "green" drive. The HDD is going to get less use than a home desktop computer HDD. Freeing your archival storage from the performance requirements of recording video means you can get a lot more storage for your money.

3) The write durability of a SSD might seem to be a concern. But even worst case if the flash dies after 500 writes, the 256 GB SSD can survive 128 TB of writes. I'm generating about 35 GB of motion-activated video per day, so that will last 10 years. If the flash lasts a more realistic average of 1000 writes, it'll last 20 years. I can live with replacing the SSD every 10-20 years.

4) But SSDs are expensive! The $170 cost of the SSD was trivial compared to the $3000 in cameras, cabling, and installation. The same could be argued for the cost of these WD Purple HDDs, but why pay for that sort of performance and durability in the entire storage system. You really only need it in the portion of the system which is continuously being written to. Most of the rest of your storage just holds the video files for ~100 days.
 
If it's motion-activated, an SSD is great (though you could probably just read it into a RAMdisk or something, depending on how big the chunks are.

I'd be worried if you were keeping a rolling window of data on an SSD, though, which is probably what these are for.
 
Sep 22, 2013
482
0
10,810


Again, though I think you're missing the point here.

SSD's may be very capable from a performance standpoint for your uses, but they aren't known for long-term durability. Their tolerance for multiple read/writes over time is still less than a surveillance drive, even if that drive is much slower.

The durability isn't just for the physical parts, either. A failed SSD is a failed SSD, and a bad write means it's gone. On a platter, this data can often be recovered if needed. If it's a bad write to flash, there's no redundancy; no part of a file lives on a different platter.

Security isn't about speed, it's about lifespan and reliability. You can't risk losing valuable data to a faulty drive head, motor or plate that wears out quickly, which is why since HDDs are the surveillance standard for *other* reasons, they need to be beefy to standup to wear and tear.

In your unique case, your HDD only gets written to a few times a day because of your cache configuration, which is a choice, not a forced configuration. Sure, if you're actually using the same computer for personal use and recording surveillance at the same time (which is a terrible idea) then this might benefit you. But for systems that are dedicated to surveillance, it makes no sense.

There's also the consideration of a power failure. SSDs don't always have the power protection in place to prevent a data loss in the event that power suddenly fails. I hope you purchased a drive that has power protection.

Last, an SSD is not only a terrible choice for security, it's also pointless. There's no need for the read/write speed you're getting for continuous write.

If I were configuring a surveillance system, I'd definitely be looking at some of Seagate's options (used by the US military, among others, though certainly not their exclusive choice) and considering a mirrored RAID array.
 
Status
Not open for further replies.