4 ms·
The MTBF and MTTF has been so perverted by the drive vendors as to be useless. The 233% makes sense as "failures per purchased drive over 3 years". (or whatever
by jws 15y ago
The MTBF and MTTF has been so perverted by the drive vendors as to be useless. The 233% makes sense as "failures per purchased drive over 3 years". (or whatever period that is)
Seagate is now using "Annualized Failure Rate" on their drives which is MTBF evaluated for the expected number of power on hours in a year (the first year).
The Barracuda Green series gets the new one year warrantee, but boasts a 0.34% AFR in Seagate's specifications. That is on the order of only 1 drive in 100 failing over a 2 year period. Who in their right mind would cut their warrantee to one year if this was really the case?
- ComputerGuru 15y agoAFR is fundamentally misleading. The percentages are compounding, and the probability of the drive failing "within this year" is only fixed if you restart your state machine. In reality, people don't look at whether the drive is going to fail "within the next year" but rather "this drive has failed and I've only had it for x years." MBTF may have been perverted by PR and marketing departments, but as a mathematical concept it is perfectly sound and indeed the ideal measure for failure rates. The solution isn't to make up a misleading statistic and label it as the new "easier to understand metric," while in reality most home users would feel royally screwed if their drive(s) failed within say 3 years of purchase. The solution is to stick to math and statistics and use mathematically-accepted derivations of MBTF that are rigorously upheld and pinned to an honest metric.