Data Doctors: No way to predict hard-drive life

Q. How long should a hard drive last, and are the new solid state drives going to be more reliable? — Peter

A. Today’s hard drives are faster, store more information and are more reliable than ever. But just like any other electronic device, they have the possibility of failing.

Current hard drives are designed to run nonstop for years and have warranties that range from one to five years. But that is of little comfort if a 6-month-old drive full of your family photos, address books or financial information fails and you don’t have a backup.

A thin attempt at trying to rate the life of a hard drive through MTBF (Mean Time Between Failure) has been around for a long time, but the reason I call it “thin” is that each manufacturer uses different parameters for publishing this spec.

An MTBF of 700,000 hours equates to about 80 years, which is NOT how long you can expect the hard drive to last but a rating based on a bunch of math the manufacturer used that can be misleading.

MTBF has become, in the words of a pundit on the Internet, “a statistical measure that we are not supposed to believe,” so don’t take it at face value. Based on our Data Recovery Lab’s experience over the years, a high MTBF rating is fairly immaterial because the vast majority of the failed drives we are asked to recover data from are less than 3 years old.

What makes a hard-drive failure unlike any other type of electronic failure is that, not only do you lose the use of the device, you potentially lose all of the information stored on it. Think about how unfortunate the failure of your DVD player would be if all your movies and family videos disappeared along with it.

Despite the age and mechanical nature of magnetic hard drives (which were first created in 1956), it continues to be the most economical way to store large amounts of information. For almost the entire 20-plus years that I have been involved in the computer industry, I have been hearing the prophecies of the “end of the magnetic hard drive.”

Despite all of the various alternative storage technologies that have been developed, none has been able to overcome a simple economic equation: the cost per megabyte.

The most recent entry into mass storage is the solid state drive (SSD), which is based on the same technology as your digital camera’s memory card — just a lot bigger and a lot more expensive.

As a point of reference, the current price for an 80-gigabyte SSD is over $1,500, while a magnetic 80-gigabyte drive is less than $60. The SSD’s cost per gigabyte will have to come way down before the average Joe has any interest in owning it.

While it’s true that SSDs have no moving parts, there are no data that suggest they are more reliable as a result. In fact, some are suggesting that since chip failure is more common than drive failure in today’s personal computers, it might actually make SSDs less reliable in the long run.

The most interesting thing that I have seen from the mass storage community is what is being labeled “hybrid” hard drives (HHDs). Hybrids incorporate the best of today’s magnetic technology with a very large solid state “cache” drive, which makes the drive faster and consume less battery life. That makes them ideal for laptops.

There are some drawbacks to this method of data storage and access, so the jury is still out as to whether this combination is worth the extra money.

What you really need to take away from this column is this: There are only two kinds of hard drives — those that have failed, and those that are going to fail.

So plan accordingly and backup, backup, backup!