Date: Fri, 27 Mar 2015 11:58:34 +0000 From: Igor Mozolevsky <igor@hybrid-lab.co.uk> To: Mark Martinec <Mark.Martinec+freebsd@ijs.si> Cc: Hackers freeBSD <freebsd-hackers@freebsd.org> Subject: Re: Seagate Archive HDD Message-ID: <CADWvR2gQsk-peNxLo4afueotSA-EVHwJbL-=jZx-zYCyu1F5WA@mail.gmail.com> In-Reply-To: <b49762f2489c21ffd82b728f5957003e@mailbox.ijs.si> References: <alpine.BSF.2.20.1503261124380.1417@laptop.wojtek.intra> <CADWvR2jCP0UT4DLWsfwwJ6qoBauDmuBDdHAfeMpfJPGNSB3-cw@mail.gmail.com> <alpine.BSF.2.20.1503270936080.719@laptop.wojtek.intra> <CADWvR2g8_PBmGXPF0nMctsJ2RxWvPwYKV9PHVru5qwdk9UcE4w@mail.gmail.com> <b49762f2489c21ffd82b728f5957003e@mailbox.ijs.si>
next in thread | previous in thread | raw e-mail | index | archive | help
On 27 March 2015 at 11:05, Mark Martinec <Mark.Martinec+freebsd@ijs.si> wrote: > 2015-03-27 09:56, Igor Mozolevsky wrote: > >> On 27 March 2015 at 08:36, Wojciech Puchar <wojtek@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=E2= =80=A6 >> > > > 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=E2=80=A6 HSGT have a whitepaper "for the masses" on the topic: "=E2=80=A6 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=E2=80=A6" [1] 1. http://www.hgst.com/tech/techlib.nsf/techdocs/FEF3B52BFE9A054586256E66005AA= 389/$file/WP_AV_25March.pdf --=20 Igor M.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CADWvR2gQsk-peNxLo4afueotSA-EVHwJbL-=jZx-zYCyu1F5WA>