Some internal hard drives are advertised as "optimized for surveillance storage" (and similarly, "optimized for gaming").

What makes these types of drives special or different from "standard" hard drives? Or is it just an advertising gimmick which allows them to pad more money onto the price?

A hard drive is just a hard drive, isn't it?

  • As I understand it, surveillance hard drives are designed for lots of sequential writes and optimized for continuous, non-stop operation—which is precisely the sort of workload encountered in a CCTV storage device. – bwDraco Nov 1 '14 at 1:21
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    Off-topic, but some related info: NAS-optimized hard drives are also designed for 24/7 operation, but are tuned for use in a RAID environment and support ERC/TLER/CCTL. – bwDraco Nov 1 '14 at 1:25

It should have with sequential / random Reading and Writing speeds to do. A harddrive which is "optimized for survelliance" have optimization on its sequential Writing rate, and a pretty decent sequential Reading rate, but random rates are really crappy. Thus its optimized for survelliance Tools which writes data in a steady nice stream.

A gaming harddrive should have a equal weight on all rates, since a game might need to read many small random files, but also a couple of large "stream" files like cutscenes, maps, textures and such. Eg, a gaming harddrive should have the highest possible random rates. Since technically, the sequential rates cannot be worser than random rates (a sequential access is implicitly random, but a random access can or can not be sequential access), thus a gaming harddrive is the opposite of a survelliance harddrive.

A standard harddrive is somewhere between survelliance and gaming.

There is also harddrives that is more designed for long-term storage, and those have a high read rate but bad write rates.

So a drive manufacturer can "concentrate" on specific rate, giving disadvantages on other rates, that then gives the different drive types "survelliande", "gaming", "standard", etc.

However, any drive CAN be used for any purpose. Everything that identifies as a "drive" in a computer is just a simple flat storage area, that can be used for any data storage.

  • Do you have any reference for that? How, specifically, could a drive be designed to be optimized for writing? – slhck Nov 1 '14 at 7:13
  • It all depends on the Circuits and prioritizations. For example, a drive which prioritizes queued write commands Before any queued read commands would for example have a higher write rate than read rate. Manufacturers of drives can really do very much with firmwares and the internal workings to achieve superior performance for a specific use case. Sometimes its just a firmware adjustment to make a drive "survelliance optimized". Its not just a "marketing gimmick", its really a optimization in the drive to make it more suited for survelliance. – sebastian nielsen Nov 1 '14 at 9:11

Drives that say they are optimized for surveillance should be using a part of the ATA standard known as the Streaming feature set. This feature set places a priority on processing the data quickly, rather than the quality of the data itself. The end result of this is very low or no frame loss, which is what you want in a video capture system. If your camera spots the bad guy doing something but the hard drive fails to capture the frame(s) from the camera, what's the point?

Also, these drives are designed to be on 24/7, as surveillance systems are typically on all of the time, much like server hard drives.

UPDATE: I don't have a specific source, because implementing this feature set is not mandatory. That is, there is no rule that says that in order to call your drive a surveillance drive, you must implement features X, Y, and Z. You would have to check with each manufacturer to see if they implement the feature set.

You can, however, look at information about the ATA/ATAPI command set, such as the one at http://www.t13.org/documents/UploadedDocuments/docs2009/d2015r1a-ATAATAPI_Command_Set_-_2_ACS-2.pdf. Section 4.24 describes the Streaming Feature Set and indicates,

This feature set is defined to satisfy the requirements for AV type applications.

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    Adding a source or two would make this answer a home run. – Twisty Impersonator Nov 1 '14 at 4:07
  • See e.g. techarp.com/showarticle.aspx?artno=659&pgno=4. These drives give up quicker on bad sectors. – MSalters Nov 1 '14 at 7:05
  • ...TLER, in other words. – bwDraco Nov 1 '14 at 19:43
  • "This feature set places a priority on processing the data quickly, rather than the quality of the data itself." This doesn't make any sense. What's the point of the drive writing the data quickly, if the quality of the write isn't a priority? Any plain old (well, plain modern) 7200 rpm HDD can sustain about 100 MB/s write, which is plenty: it's fast enough to fill up a 4 TB drive in about half a day. – a CVn Nov 3 '14 at 9:53
  • Writing the data quickly helps reduce pixelation and interruptions. I think the drive manufacturers can explain it better than I am. Look into the Western Digital Purple drives, for example. – Patrick Seymour Nov 4 '14 at 23:03

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