Can a hard drive be used upside down? 5 reasons why you shouldn’t

Have you ever wondered if running a hard drive upside down or on its side might be causing it damage or making it less reliable?

According to the major hard drive manufacturers hard drives can be used in any orientation along an X, Y, or Z axis so long as they are not tilted. To mount a hard drive upside down ensure it is level and has good ventilation and it will work as normal but the cons may outweigh the pros for doing so. 

There are plenty of use cases where you might want or need to mount a hard drive upside down, in this article we look at the why you can and why you probably shouldn’t.

Why can you use a hard drive upside down?

Hard drives store data on disks that are accessed by read/write heads on the end of an armature (like a record player). The disks inside a hard drive are double-sided so no matter which way up a hard drive is one side of the disk is being used upside down. Imagine a record player that could play both sides of the record at the same time. In bigger drives, it would look like a record player that could play both sides of several records at the same time. 

The distance between the disks and the read/write heads can be measured in tens of nanometers so there is very little tolerance in the design meaning that being upside down would have little effect on the proximity of the disks to the read/write heads.

Why would you use a hard drive upside down?

There are various reasons you might need to use a hard drive upside down or on its side, the main one that springs to mind is space-saving, I have outlined two examples of when I have used a hard drive upside down below.

The first time I asked whether I could use a hard drive upside down wasn’t because I wanted to, it was because I already was! I looked over at my external drive halfway through a backup and realized it was upside down. I knew better than to flip it halfway through a back up so searched the manufacturer’s specifications and found that it didn’t matter so long as the drive was flat or perpendicular to flat (on its side). I let the drive finish the backup and everything worked as expected. In fact some external drive housings mount the drive in a vertical position, this can be on its head or on its side.

The only time I mounted a hard drive upside down was in an old pc case where I had a 2.5″ I needed to mount into a 3.5″ slot. I fashioned an elaborate mount out of a small Tupperware dish only to realize I had marked all the holes upside down. I left it that way and used the disk upside down and though that pc is long gone, I still use that drive today.

5 reasons you shouldn’t use a hard drive upside down.

As my mom taught me from a young age, just because you can do something doesn’t mean you should. 

Hard drives are mechanical devices that read and write data to and from a spinning disk. Any spinning parts are subject to centrifugal force and other more complicated physics like a gyroscopic precession. To read the disk an armature is used that has a head on it that can code and decode the data much the same way a record player works.

These moving parts are fragile and very precise and this is why it is not recommended to move or jog a disk while it is in use. You can cause the head to skip or you can cause unusual physical forces to be exerted onto the spinning disk, like the aforementioned gyroscopic procession which has the effect of tilting the disk perpendicular to the direction that it was physically moved in causing stress to the spindle and disk itself.

1. It has a top.

If something can be upside down that means it can also be the right way up and if there is a way to differentiate the two then it stands to reason that a hard drive has a top and that hard drives are designed from the ground up. And in my experience, if something has a top and has been designed and built-in that orientation then it is probably a good idea to keep it in that orientation.

Put it this way, nobody, if a hard drive fails, is going to wonder if it failed because it was the right way up. But there may be cause to speculate if it’s upside down or on its side.

2. The bottom is exposed.

Now we have the giggles out of the way, it’s worth noting that hard drives have exposed circuitry on their underside. It is within reason to speculate that something conductive could fall into the circuitry and cause a short, frying the boards and potentially corrupting the disk and making data irretrievable. For that reasoning alone I have not returned to my DIY cowboy days of yonder and instead, I buy the correct mounts for the correct slots. You may continue giggling now.

3. It might get flipping tired of it.

While I can’t find any data to back this up I have read comments and found anecdotal data that suggests that flipping the drive regularly so it is operating in different orientations put undue wear on the parts. All I can say about this is it makes sense and it’s always wise to air on the side of caution with data storage. So if it is upside down, leave it that way if it needs to be, or turn it over now and leave it!

4. If it is a really old hard drive, like really old.

Running upside down is not recommended on any drive old enough to require you to actually run a DOS command to be able to park the hard drive head before you even turn off the computer. These drives do little to protect themselves like newer drives and are best run as level and as carefully as possible.

5. Someone might try to correct it.

That might seem like an odd reason but I remember being on a film set watching the digital imaging technician backup drives and an assistant reached over and flipped the drive informing him it was upside down. I have never seen such levels of nerd rage in my life as I did that day. But this is a scenario I could see being played out almost anywhere by an unwitting but helpful passer-by.

Why you shouldn’t tilt a hard drive.

As we have outlined an HDD has spinning disks inside and a head on an armature that accesses the data stored there. Anything spinning is subject to some interesting physics that doesn’t apply to things that aren’t spinning. The main two things to consider are centrifugal force and gyroscopic precession.

Centrifugal force is the force generated by spinning that drives the mass outward from the center point. There are plenty of videos on youtube demonstrating the potentially disastrous effects of too much force. For example, spinning an apple on a jet of air until the apple explodes. This isn’t going to happen to an HDD disk as they spin within tolerances but they do spin and the centrifugal force they generate needs to be balanced. Imagine spinning a basketball on your finger, it is possible because of the gyroscopic effect that essentially balances the ball. The disk itself needs to be balanced in order to spin in a single plain.

This leads us onto second thing to consider…

Gyroscopic precession. If you have ever played with a gyroscopic toy or tried spinning a bike wheel on your finger you will notice a strange effect and that is that the spinning object will tilt out of phase, meaning if you tilt it forward it will fight you and tilt itself to the left or right depending on the direction of the spin.

These few physics phenomena mean that if you tilt a hard drive while it is spinning then there is a high chance you could cause the disks themselves to tilt, especially any sudden movements. This tilt can cause the head to collide with the platters and can completely destroy a hard drive.

A lot of hard drives come with an accelerometer that can detect movement and resets the head to the ramp to avoid these collisions, this is typical of laptop hard drives and you may notice a clicking sound when you pick up your laptop or move it, this is the head disengaging and the disks stopping.

Conclusion.

Always check the specification from the manufacturer before mounting a hard drive.  While most hard drives are specified to be able to work perfectly well upside down there are a reasons that doing so might lead to adverse situations that result in data loss. I would always air on the side of caution and not mount a drive upside down unless I had to. In any case, make sure all of your data is backed up!