Types of Storage

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Types Of Storage

Next we'll cover a few terms related to hard drive storage for video. Afterwards is a summary of different storage solutions for various video formats.

SATA: (Serial ATA) These are types of drives that ship as the internal drive in newer computers. If additional SATA drives are installed, they are fast enough for some video storage. Basically only fast enough to run DV, DVCPRO HD (720p) and HDV. This standard is quickly replacing the older ATA (Advanced Technology Attachment) as it supplies faster data transfers. The latest current standard is referred to as SATA 3.0 Gbit which provides a 3 Gbit/sec communication rate.

eSATA: Standardized cabling and connectors to interface externally connected SATA drives.

FireWire: FireWire drives are actually a type of ATA drive inside an enclosure with an ATA to FireWire bridge. Single FireWire drives are similar in speed to standard SATA drives and are generally fast enough for DV, DVCPRO HD (720p) and HDV. Not all FireWire drives have the same speeds though. Be sure to look for a drive that is meant for video storage, and is at least 7200rpm.

RAID: (Redundant Array of Inexpensive Disks). A RAID is several hard drives that are grouped together to act as a single disk. In certain configurations they are capable of much greater speeds than individual drives. Depending on the configuration, they may also be capable of redundancy, in other words, if one of the drives in a RAID goes bad, the information is not lost as the information is being distributed in duplicate across the drives. Some RAID configurations are capable of both greater speed and some type of data protection. Only RAIDS are capable of handling uncompressed SD or HD video, as well as other formats like DVCPRO HD 1080i or 1080p. Not all RAIDS are created equal, so careful investigating is needed to determine what is needed for your particular needs. For example, you can buy an inexpensive FireWire RAID of two drives that can handle a bit more, like uncompressed 8-bit SD video, but nothing beyond that. On the other hand, a more expensive solution like a Fibre Channel connected RAID like Apple's XServe RAID is capable of uncompressed HD resolutions.

RAIDS Levels

Which RAID setup is correct for your needs? Here's a basic breakdown of three of the different RAID "levels".

RAID 0: Referred to as striping, this RAID level increases performance (throughput) over that of single drives. The downside is that there is no protection against data loss, so if one drive in a RAID fails, data across the entire RAID is lost. Despite this, RAID 0 is the best solution for low to medium budget projects with increased bandwidth needs. RAID 0, depending on the system and amount of drives in the RAID, can be configured for many different bandwidth needs, from highly compressed formats to uncompressed SD and HD editing.

RAID 1: Referred to as mirroring, this RAID level is used to protect against data loss. If one drive in a RAID 1 configuration goes bad, the RAID will continue to function. This level does not have much performance enhancement though, and is best suited to protect data from loss, but not really suitable for video editing demands.

RAID 5: Provides increased performance as well as parity protection against data loss. The RAID will continue to function if a drive in the array fails. Better solution over RAID 0 for bigger budgets and higher resolutions. RAID 5 is used in Apple's XServe RAID. Not only will the system continue to perform if a drive fails, but as another drive is replaced and is being rebuilt by the system, the RAID will still continue to function, allowing increased productivity as editors can continue to work (although the RAID will operate at less than full performance until the replaced drive is rebuilt).

*Note: There are other RAID levels not defined here.

Overview Of Storage Options

As you can see from the charts in the article Storage Requirements, not all video formats are created equally. So our storage requirements will vary depending on the formats of video you'll be working with. The following is just a basic, broad look at your options.

Single FireWire 400 drives: these drives are fine for DV, HDV and possibly DVCPRO HD 720p.

Single FireWire 800 drives: these drives are fine for DV, HDV and DVCPRO HD 720p.

FireWire 800 RAIDs: Depending on how many drives are striped together in the RAID, these systems can handle DV, HDV, DVCPRO HD 720 and 1080 formats, upwards to potentially being able to handle uncompressed SD 8 and 10-bit video (one stream) and Apple's ProRes formats for HD. These RAIDs connect to the computer via a single FireWire 800 connection.

SATA RAIDs: (Internally connected, or external eSATA RAIDS). Similar to the FireWire 800 RAIDs, these systems may be capable of handling the above mentioned formats, and possibly up to uncompressed HD, depending on the specific format. For uncompressed SD, you'll likely need at least 4 drives striped together and for uncompressed HD you'll likely need 8 drives striped together. These RAIDs connect to the computer via a eSATA cable(s) to a eSATA PCI card in a desktop computer.

Fibre Channel RAIDs: A RAID is connected to a desktop computer via a fibre channel card. These RAIDS are capable of different configurations which can allow high transfer speeds and data backup protection. These RAIDS (depending on the configuration and amount of drives striped together) can handle data rates of 2K, uncompressed HD and all the other formats listed above.