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Data hastighet för Raid och SD

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Håller precis på att kolla runt efter en raid lösning som ska funka med mitt Decklink Pro kort. Alltså ett Raid-system som klarar av video i SD upplösning.
Tänkte bara kolla om någon har dataöverföringshastigheten för SD i mb per sekund.

  • Oregistrerad
  • 2003-12-11 16:13

Enligt Maxtor, här: http://www.maxtor.com/en/documentation/white_papers/av_white_papers.pdf

finns det 2 typer av SD, high and low och de kräver 15 resp. 4 MB/s. Uncompressed kräver 24 och lägsta HD som var specat kräver 60 MB/s.

Här finns en produkt: http://www.digiverse.co.uk/pdfs/DV_Project.pdf

även Granitedigital: http://www.granitedigital.com/ har FW-lösningar med 40 MB/sec vilket borde räcka?

Cool:)

Ska kolla upp det Raid kortet för interna hårddiskar som macotett säljer det verkar bar

  • Oregistrerad
  • 2003-12-11 16:37

Här är vad Aja rekommenerar för sitt Kona-SD kort:
40 MB/Second Sustained
80 MB/Second Sustained for RT Effects

Följande info är från DeckLinks hemsida ang. diskar för SD:

TITLE: Disk arrays for uncompressed SD video.

TOPIC: What kind of disk do I need for uncompressed video?

DISCUSSION

Although it's possible to work with JPEG and DV on your internal IDE disk that's standard on all computers, uncompressed video uses higher data rates, and requires special consideration for capture disks.

Uncompressed video is great quality, however the data rates are higher than commonly seen on computers, so a single hard disk is not fast enough to capture or play back uncompressed video. The solution is to use more than a single hard disk, working together so they are much faster.

Disks are "striped" together to build an array of disks. Striped disks work together to store the data and so the overall data rate per disk is much lower. This stresses each disk less, and you can store higher data rates than a single disk can handle.

You can get all kinds of disks, and these vary in speed. You can get a simple disk box and place a few hard disks in it, or you can even put the disks internally in the computer if space is available. The types of disk arrays where disks are connected together are commonly called JBOD, or "Just a Bunch Of Disks" arrays.

These are then striped together with software such as Apple Disk Utility's raid feature. These disks will then appear on your system as a single disk. You can then select this as the capture location in your QuickTime software.

Recommended disks for building disk arrays is Seagate™ Cheetah™ Ultra 160 SCSI disks. These disks are fast, and work great for real time effects. For single stream simple capture and playback up to 10 bit uncompressed standard definition, you can use 2 Cheetah disks. For dual stream real time effects such as dissolves, 4 or 6 disks can be required.

Mac's don't come with Ultra 160 SCSI built in, so to connect Ultra 160 SCSI disks you will need to add in a SCSI PCI card. We recommend the ATTO UL3D dual channel Ultra 160 SCSI card or the UL4D dual channel Ultra 320 SCSI card.

Another disks solution for uncompressed video is the IDE pre build disk arrays. Unlike JBOD disk arrays you build yourself, prebuilt hardware RAID disks can offer hardware protection for video data in case of a disk fault. If disk fails, the disk array keeps working until you can get the disk fixed, and valuable data is not lost.

Currently Mac OS X support for IDE based pre build arrays is poor, and Medéa is the only company who have added full Mac OS X support. Medéa Videoraid RTR disks with v148 firmware have been tested by us, and work great.

We also recomend the Apple Xserve RAID, and this works well for uncompressed video.

Because disks systems are always changing, the best recommendation for disk array options is your dealer. Often dealers will know of other lower cost, and faster disk solutions because they can keep up easer with the many brands and options available worldwide.

ADDITIONAL INFORMATION

www.medea.com
www.attotech.com
www.seagate.com
http://www.apple.com/xserve/raid/

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