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Section - [8] Solid State Disk (SSD) Frequently Asked Questions (FAQ)

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From: Solid State Disk (SSD) Frequently Asked Questions (FAQ)

*Note: This section is a slightly trimmed and editted version of the
SSD FAQ from Robert at DES ( which I think
he also posts to c.d.sybase. I would take the "up to 1000 times
faster" claim with a grain of salt, though the general info is good.
--rdv, 94/9/15

1) Q. What are solid-state disk emulators?

A. Simply put, solid-state disk emulators are Dynamic Random Access
Memory (DRAM)-based storage devices that appear to the host exactly as a
magnetic rotating disk.  DRAM chips, which are ultra-fast devices
that store data while the system is on, increase data access, thereby
eliminating I/O bottlenecks that constrain overall system performance.

Solid-state disk emulators can be either volatile or non-volatile,
meaning that they are able to retain data when the system is turned off.
DRAM alone is volatile.  Solid-state disk emulators that are designed with an
integrated backup system are non-volatile storage devices; if a power
outage occurs, the user's data is protected by the backup system and will
not be lost. Solid-state disk emulators are volatile when methods for
backing up data are absent.  A power failure will cause data to be
lost on a volatile solid-state disk.

2) Q. How do solid-state disk emulators work?

A. Solid-state disk emulators plug into a computer's I/O controller.
Typical client/server systems use the ANSI-standard SCSI interface on
its I/O controller.  It is plug-and-play because it emulates a
rotating disk.  No special drivers or operating system patches are
required to make it work.  In addition, because there are no moving
parts, seek and rotational latency times are zero, which aids
solid-state disk emulators in performing up to 1000 times faster than
magnetic rotating disk drives.

3) Q. What applications are well-suited for Solid State Disk?

A. In general terms:  1) transaction processing, 2) batch processing, and
3) query or decision support analysis. Many types of application
software can take advantage of the super-fast access times SSD offers.

4) Q. How reliable are Solid State Disks?

A. Based on real world user data from a large SSD site, the actual power
on hours mean-time between failure is greater than 1,000,000 hours. Since
this site has yet to have a failure, the number is likely to go up.

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Last Update March 27 2014 @ 02:11 PM