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High
Performance & Protection
Working with digital media such
as DV (Digital Video) requires huge amounts of resources.
Large capacity storage systems combined with high performance
/ large bandwidth - are a prerequisite to enable delivery
of high quantities of media data. Storing and editing huge
image files or sequences for film and video production requires
high-speed data processing capabilities flexible enough
to work with a multitude of software tools.
Independent
RAID array system are completely independent of the operating
system or application layer, and provide large capacity
with high data throughput to any platform equipped with
a suitable Ultra-Wide SCSI, Ultra2 LVD SCSI, or Fibre-Channel
interface.
Fibre
Channel Technology
Fibre Channel is ideal for video applications
because of the advantages it provides the user -mainly faster
transfer rates, network scalability /expandability, single
fibre or coax connections for long run lengths and unlimited
file transfer sizes. Fibre Channel is extremely flexible
and is designed for use on any platform and application.
It can be used over distances up to 10 km (about 6.2 miles).
This
is in direct contrast - and far superior to - the traditional
SCSI interface which has a limit of only 5 metres in Ultra-Wide
configuration, with a maximum throughput of 40MB/sec. Ultra2
LVD (Low Voltage Differential) SCSI has addressed some of
these limitations by raising the distance between host and
termination to some 15 metres and doubling the bus throughput
to 80MB/sec.
Fibre
Channel is compatible with - and often provides bridges
and routers to - other networks such as IP, SCSI, HPPI and
ATM. For more information on Fibre Channel click
here.
Data
Rates and Capacity
Uncompressed video storage requires data
rates from 21 MB/sec or 270 Mbits/sec (YUV 422) to over
300 MB/sec (HD 1080 x 1920 RGB). Faster than Real-Time transfers
for video movement through a facility increases these requirements
even more. At 100 MB/sec, Fibre Channel RAID sub-systems
can support these high video rate requirements in single
chassis configurations and multiple RAID combined with dual
loop Fibre Channel (FC-AL
- Fibre Channel Arbitrated Loop) configurations
can support the High Definition Video rates for requirements
over 100 MB/sec.
Why RAID?
In a RAID Array, data is striped across
multiple disk drives connected in parallel. The minimum
number of drives required for higher performance is two
- a simple striped array with no parity.
To
implement RAID levels 3 or 5, a minimum of three disks are
required. One of the three disks (Level 3) will be
used to store parity, or the equivalent capacity of one
of the disks (Level 5).
The
capacity lost to parity calculations drop in proportion
to the number of disks: 33% with three drives, 25% with
four drives, 20% with five etc. In an eight disk array for
example, the sum total of seven drives would be theoretically
available for actual storage and the equivalent of one disk
is dedicated for redundancy or parity information.
For
detailed information on RAID levels, their uses and implementation,
please see our Technical
Section.
The
Future of SCSI
Contrary
to some popular belief, the advent and introduction of FC-AL
may well give the sale of SCSI peripherals and devices a
boost. The Fibre Channel specifications includes a full
subset of the SCSI standard, meaning that all SCSI devices
can operate within a FC environment with no additional infrastructure
or changes to existing systems.
The
high throughput and bandwidth offered by FC enables SCSI
to operate at the maximum level available. By moving existing
storage systems to FC-AL and incorporating RAID technology
into the equation, the increases in performance & bandwidth,
combined with the security & protection of your data,
can be a tremendous boost in stability, confidence, and
efficiency within your organisation.
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