Robert,
The data you presented
MTBF: 100,000 hours
Service life: 5 years
Bit error rate: 1 in 10 to the 12 power
This data remarks on the expected reliability of the average drive if everything is working.
The average person works 2,000+ hrs per year, so if you use your zip drive 100 hrs/yr, then it will take 1,000 yrs to reach mean failure rates (when 50% of drives fail). This suggests a LINEAR failure rate of 0.05% PER YEAR. An EXPONENTIAL failure rate suggests a LOWER failure rate in the first few years (its supposed to get worse as it gets older).
Bit error rate is when the read/write head screws up on a bit read. It happens.
COD failures at "a fraction of 1%" gives no understanding of the problem.
The worse case postulated is 120K dead or 1% of outstanding sales. The best case is less than 12K units dead (that is grossly an underestimate, IMO) or 0.1%
This is supposed to account for all DOA, misc. failures + COD failures.
I wonder if IOM is asking the COD owners about their usage habits, and the average age of their drives? Are they successful in debugging the source of COD?
Basically, if 0.5% of the drives have died since shipment, then their failure rates do not support MTBF: 100k hrs.
Right now, I can't afford to buy a zip, for fear of COD. Which leaves me with a JAZ option, which is too much and too expensive...
BL |
