Dave wrote: > Well..... I did a search of MTBF for Compact flash cards and I found > everything from 500,000 hours to 4 million hours of operation. Since > 500,000 hours is 57 years, then 4,000,000 hours is about 450 years. > This MTBF stuff is TOTAL crap! It all comes from a reliability estimation guide by the Defense Electronics Supply Center that was written during the Vietnam war to quantify equipment reliability for military equipment in the field, and doesn't have a life figure for integrated circuits, but they do have numbers for discrete transistors and resistors. You estimate the worst-case internal temperature for each component and plug it all into a formula, with the number of each kind of component, and it is supposed to give you an MTBF (or actually FIT, "failure in Time") figure for the entire unit. It is so far out of date compared to the components we use today, it would be totally laughable, if the uneducated weren't taking these phony numbers as Gospel! I've seen disk drives with 800,000 hour MTBF listed on the data sheet. When you pin them down, they say "Oh, that is for the electronic part only, not the heads, spindle bearings, disc platters, etc." The latest batch of ultra-sub micron scale chips are predicted to have a MUCH lower MTBF than previous generations, due to electromigration and hot carrier effects.
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