14 DAY TRIAL // Just about when I was going to buy a new hard drive, I came across this news article about the reliability of Mean time between failures (MTBF), as being given by the hard drive manufacturers. It's an independent study made by the Computer Science Department at the Carnegie Mellon University. They have taken information about approximately 100.000 hard drives over periods of time between five years and a lifetime of service, in order to verify the real MTBF for those drives.
Interestingly enough, the numbers they were able to obtain don't actually match the ones provided by hard drive manufacturers. In the paper, it is mentioned that for a hard drive that specifies from 1.000.000 to 1.500.000 hours as the MTBF, there is a nominal failure rate of about 0.88%. The reality is different, hard drives replacement rates exceed 1% and go up to 13% per year in some unfortunate cases, unfortunate for the users or the systems in which these hard drives will find a home.
Having these numbers in opposition to the ones supplied by the hard drive manufacturers is somewhat of a problem for any user, because the study revealed that the temperature of the operating environment of a hard drive has little effect on failure rates, whether that environment is cold or hot. The range of hard drives being used in the test includes anything from Serial ATA, SCSI and Fiber Channel.
The failure rates were also in significantly large numbers for the Fiber Channel drives, the Serial ATA drives thus becoming just as reliable as their much more expensive counterparts. In fact, the main reason for which hard drives fail is the amount of time they spend powered on. Therefore, if you are a normal user who uses the computer for personal purposes and your computer is working as long as you are at home, the hard drive should yield a life expectancy of 5-7 years, whereas if it's being used in industrial applications, the time frame decreases, add it to a RAID matrix, lose some life expectancy, and so on. So go out and buy yourself that new hard drive, it'll last as long as any other.