H D D l i f e

What Google Doesn’t Know About HDD Temperature That You Should

Studies conducted by Google and Backblaze in the same breath conclude that “As long as you run drives well within their allowed range of operating temperatures, keeping them cooler doesn’t matter” and argue “…the lack of a consistent pattern of higher failure rates for higher temperature drives...”. The bottom lines of the studies seem very well grounded, but does the story end here?

We insist – temperature of hard disk drives matters much more than Google and Backblaze think it does.

Hot or not?

So, what the problem with hard disk drives getting hotter? As you might know, HDDs store data on a ferromagnetic surface of its platters. Each individual bit of data is physically represented by a small domain of magnetization. The direction of magnetization represents either binary zero or binary one.

The problem with the temperature comes from the fact that the magnetic material of HDD’s platters, if heated, starts loosing its intrinsic ability to preserve direction of magnetization when no external magnetic force is applied. Simply put, zeros spontaneously can become ones and vise versa. Even worse, if the temperature further increases, the material loses its magnetic capabilities completely, which means this part of the hard drive can neither be written nor read anymore.

What are those temperatures? All modern hard disk drives use magnetic film made of cobalt-based alloys. Normally, such alloys are pretty heat-resistant. You would have to throw a chunk of such alloy into a furnace to make oriented magnetic domains in it become chaotic. Not true for ultra-thin films of cobalt that are used in HDDs, though. The Curie point (that’s how the temperature at which materials lose their magnetic properties called) of such thin layers of cobalt alloy is much, much lower. Also, thin films demonstrate higher sensitivity to temperature overall. Translated to normal language, this means hard drives are prone to temperature failures due to mere physics underlying their functioning.

Hot Disk Drive

Both Google’s and Backblaze’s studies researched impressive numbers of HDDs. Statistically, their results are significant and reliable. Except one thing: the samples only included HDDs working in datacenters – well-conditioned rooms with strict automatic control of temperature and humidity. While we, common users do not enjoy such refined environments for our drives.

Indeed, a typical temperature of a home PC hard disk drive is about 50°C raising to 60°C or even higher in summer compared with the average of 25-30°С as seen in the studies. The reason is poor air circulation around the HDD: unlike those in datacenters, home PC HDDs are installed in a closed case, often near other heat-emitting devices like other drives, CPU and video card.

All of this makes situations Google and Backblaze describe as extreme quite common for a typical living room computer. At the same time, low temperatures (below 25°С) reported as dangerous are very unlikely to occur.

You still need to control the temperature

In conclusion, does this article mean Google and Backblaze are wrong and their studies are inconsistent? Absolutely not! They just don’t apply to home use HDDs well.

As long as you aren’t living in Google’s datacenter, the temperature of your hard disk drives still matters. Controlling it is easy today – SMART delivers all the info you need. And there are plenty of tools out there starting from built-in motherboard utilities to system information utilities like HWiNFO or HWMonitor. And of course, you can give a try to our HDDlife.


typical temperature of a home PC hard disk drive is about 50°C raising to 60°C or even higher in summer