Seagate Archive HDD

[Igor Mozolevsky]

On 27 March 2015 at 11:05, Mark Martinec <Mark.Martinec+freebsd at ijs.si>
wrote:

> 2015-03-27 09:56, Igor Mozolevsky wrote:
>
>> On 27 March 2015 at 08:36, Wojciech Puchar <wojtek at puchar.net> wrote:
>>
>>> what is a difference between "video recording" and normal SATA drives?
>>> except pricing of course.
>>>
>>
>> The "video recording" HDDs have no, among other things, internal "long
>> recovery" mechanisms (hence the price) because unlike "data", "video"
>> doesn't really care if small part of a frame gets corrupted on disk…
>>
>
>
> AV disks support ATA streaming command set, are designed to last
> in high temperature always-on streaming digital AV environments, are
> silent, with Preemptive Wear Leveling (PWL) (the drive arm frequently
> sweeps across the disk to reduce uneven wear on the drive surface
> common to audio video streaming applications)
>
> (paraphrased from WD docs)




I was saying why the AV disks are not a good idea for general purpose data
storage, not what the general idea was…

HSGT have a whitepaper "for the masses" on the topic: "… In AV
applications, it may be better to have some small segment of incorrect data
delivered in the stream than to have a long delay. Short delays may result
in the loss of only a few pixels*. A long delay in the data stream would
result in the loss of a larger block of data, which would be noticeable to
a viewer. A new Streaming Command Set has been developed for ATA drives,
which allows AV products to change drive behavior to meet AV system
requirements…" [1]

1.
http://www.hgst.com/tech/techlib.nsf/techdocs/FEF3B52BFE9A054586256E66005AA389/$file/WP_AV_25March.pdf


-- 
Igor M.