UNDERSTANDING "THE CONTROLS" OF THE NIST/LC STUDY
"THE METHOD" by which pigs fly and DVD longevity soars!
THE CONTROLS: Manipulating Optical Disc Longevity:
The NIST/Library of Congress Optical Disc Longevity Study hypothesized that manipulating "data longevity" on optical discs has three major components:
STRICT OPTICAL DISC QUALITY CONTROLS
Of the hundreds of CD/DVD brands in the world to choose from, ONLY 5 DVD-R disc brands were scientifically pre-selected for the study. Criteria for pre-selection are not disclose, however, it is safe to assume from disk testing specifications, that 2 physical properties -- that determine data quality -- were considered
However, pre-selection of a CD/DVD disc brand alone did NOT provide STRICT DISC QUALITY CONTROL.
For Example: Pre-existing micro "data errors" or "discoloring" in the "dye layer" would disqualify the disc from the study.
For Example: A "wobble" or "break" in the pre-formatted sprial track, detected before burning data to a disc, would have disqualify the disc from the study.
Only the best-of-the-best discs were used in the study.
AFTER ALL THAT...
NSIT/LC Study Hypothisis: Recordable DVD/CD Disc Recorders Cause Data Failure:
The findings of the NSIT/Library of Congress Optical Disc Study of September, 2007 revealed, the act of burning an off-the-shelf DVD-R disc with and off-the-shelf consumer grade equipment can, and many times does, reduce the life span of the DVD-R disc to -- close to a threshold of failure. This FACT did not change "in general" after the study.
(Quote from study)
"There are many formats and speeds of (CD/DVD) discs (for example, 4X, 8X, 16X…) in the market and yet there is no unified standard for the (CD/DVD) drive write strategy.
Therefore each (CD/DVD) recorder drive manufacturer develops their own (CD/DVD) drive to satisfy the write/read requirements of recordable CD and DVD discs.
As such, there is no guarantee that the (CD/DVD) recorder used to burn a disc is fully compatible with that (CD/DVD) disc. This can, and often does, lead to very high (CD/DVD) error rates immediately after recording the (CD/DVD) disc...
IN LAYMAN'S TERMS:
The DVD Recording Problem:
Firing a "laser burst" at a constantly moving "target point"-- on a perfect, "recordable DVD" -- and consistantly hiting it --is not easy.
The DVD/CD recording industry neve standardized" this recording (i.e.,burning ) process.
Firing the "laser burst", and missing the "target point" -- or even the entire track-- creates a "recording error" -- which pollutes segments of the tack -- like a scratch on the disc. These segments are called "data blocks". Too many "record errors" with in any given "data block", and the "data block" fails -- and is unusable -- same as too many scratches on a disc.
All DVD discs -- created by the millions -- are not created equal. If a disc has data tracking errors, like being slightly off-center, or the disc recorder has wear on the spindle -- causing the disc to be "off-balance" -- like a car tire -- then data errors will be even greater.
Using "off-the-shelf" DVD disc recorders and "off-the-shelf" DVD discs
The other problem is, once the "dye is burned" (activated), aging factors continue to create "errors" in "data blocks" that may alread be saturated with "errors".
as proposed in the study, is that DVD recorders create "record errors" (like digital scratches) -- while also recording "good data" -- onto
These "ERRORS" (digital scratches) push many data blocks on the optical disc -- to near failure -- immediately after burning the disc.
As a result, the "newly burned DVD" may equate to "a well used Video Rental DVD".
The major challenge to all optical disc recording equipmanet is "writing data" to a "spinning spiral data track". This conclussion is based on
What this means to YOU!
THE ACT OF BURNING A CD/DVD IS A DATA DEATH SENTENCE
A dics manufacture may claim that a disc has a (shelf or Statistical Erying) life of 45 years; however, using any disc recorder with any optical disc in any
the simple act of burning the DVD disc, pushes the DVD disc right up to the threshold of its end-of-life expectancy -- which NARA says, "is 2 to 5 years".
PARTIAL SOLUTION: STACKING THE DECKS
In Layman's Terms:
To MAXIMIZE DATA LONGEVITY ON OPTICAL DISC in NIST/Library of Congress Optical Disc Longevity Study, great care was taken to" STACK THE DECKS" -- literally -- "the recording decks" -- with bias -- to "manipluate the disc data longevity".
To implement recording bias, Special Disc Burning Stations (DBS) were build (see diagram below) by engineers, who then specially calibrated and matched -- with bias -- the "disc recorder" in each Disc Burning Station -- with bias -- to "best match" the "best-of-the-best discs" -- used in the study.
STATED ANOTHER WAY: The "burn patterns" of the disc recorders were matched and calibrated to the "spiral data track" of specific discs brands -- discs which had been pre-tested for errors and pre-screened for high integrity (details below). Yes, they "stacked the discs", too.
"Stacking the Decks" -- and "stacking the discs" -- and calibrating both for a "best match" -- TO EACH OTHER -- minimized "initial recording errors" -- maximize data integrity -- during the recording process.
THE CONTROLS -- used in THE METHOD OF TESTING -- caused data longevity to" Soar" in terms of (Eyring statistical) years!
METHOD USED -- TO INDUCE SOARING DATA LONGEVITY
Disc Burning Station (DBS): GNU Free Documentation License , Version 1.2 or any later version published by the Free SoftwareFoundationhttps://en.wikipedia.org/wiki/File:Personal_computer,_exploded_5.svg
Engineers Built and calibrated 4 "Disc Burning Stations (DBS)". These were customized with 4 different brands of DVD recording drives. Each recording drive (8), was calibrated to the specific specifications of a) pre-selected and b) culled discs in the study. These Disc Burning Stations (DBS) were re-calibrated as need throughout the study to maintain quality control for each different type disc and each different brand disc -- burned in the 4 Disc Burning Station (DBS).
THE DBS DAIGRAM: Numbers in parenthesize refer to diagram numbers in circles (above). References to component (9) may refer to either hard drive or to software on hard drive. All components are not referenced, as they need no explanation (like a keyboard) or components are not relevant to the Disc Burning Station for purposes of quality control in the study -- like the power supply (7). The brand, firmware, and level of "calibration control" over drive controller cards (6) are unspecified in the the study.
(quote from study) 4.6.2 Disc Burning Stations:
In an effort to ensure the integrity of the results, all (CD/DVD) disc burning station (DBS) computer configurations were the same. For this study, each (CD/DVD) disc burning station (DBS) consisted of a Pentium-4 processor workstation with the following specifications:
(3) Intel Pentium-4 Processor 3.6 GHz w/ 800mhz FSB,
(5) 1GB DDR2-533 MHz dual channel RAM,
(9) Seagate 120 GB 7200 rpm SATA hard drive w/ 8 MB cache,
(9) Microsoft Windows XP Pro w/ doc and media.
All (CD/DVD) discs were indexed to associate each with the particular DBS (Disc Burning Station) and DVD recorder drive used to record it. The recording drives (8) used in this study include the
The (CD/DVD) drive chosen for the particular brand of media was the (CD/DVD) drive shown to be most compatible with that (CD/DVD) media.
Each DBS (Disc Burning Station) was equipped with (9) Roxio Easy Media Creator 7, version 18.104.22.168 ENU. The same IMAGE™ was recorded on DVD media at the most compatible speed. The same IMAGE™ was recorded on all CD media also at the most compatible speed.
(end diagram references)
STRICT DISC/RECORDER CALIBRATION CONTROLS
(Quote from study) "
To determine the recorder with the highest level of compatibility with each brand of media, a limited number of recordings were made for each brand by each recorder in the four DBS (Disc Burning Stations -- which were custom built for quality control). "
"The discs were then burned by the most compatible recorder and initial error rates monitored to ensure that the recorder continued to operate correctly."
(Quote from study) "For testing CD: CD CATS SA3 Advanced (CD Disc Tester) can measure all relevant parameters of CD discs. All measurements were performed according to optical disc industry standards. All relevant parameters including correctable BLER (including E11, E12, E21, and E22), uncorrectable E32 errors, jitter, asymmetry and more were measured using this system. Unfortunately, this system is not capable of testing CD-RW type media, which is why CD-RW media was not included in this study."
(Quote from study) "For testing DVD: CATS SA300 DVD-R/RW PRO (DVD Disc Tester) and CATS DVD+R/RW PRO (DVD Disc Tester) from Audio Development were used to analyze the DVD media in this study. These (DVD disc tester) systems measure recorded and unrecorded DVD discs and include the Pulstec SDP-1000 optical (DVD dics) drive. All relevant (DVD disc) parameters including inner parity error (PIE), outer parity error (POE), jitter, asymmetry and more were measured using this (tester) system."
(Quote from study) "All (CD/DVD disc) media testers were regularly calibrated to ensure the integrity of the (disc recording) results."
METHOD OF MEASURING THE CONTROLS