Back in December 2024 I wrote a blog post about hard disk prices having remained pretty much constant over the past decade. Also, there seem to be no price cuts in the making, the technology seems to have hit a wall. Sure, HDD capacities have increased in the last decades, but so have prices per drive, and hence the price per TB is pretty much the same it was a decade ago. This might have some interesting consequences:
While the price per TB of storage has remained the same, the amount of data we are storing has not, it has constantly grown, and probably not linearly. From a consumer point of view, cameras in smartphones have gotten more sophisticated, resolution has increased and taking videos at 4K resolution has become popular. So if all memories are kept somewhere ‘in the cloud’, users accumulate more and more data. As storage prices are not decreasing, this means that users will have to pay more and more to store their rising amount of data.
However, at least the running costs per TB have decreased in the last decade. This is because drive capacities have increased and keeping those disks spinning takes the same amount of energy and space per drive, while the amount of data a drive can store has increased by a factor of around two in the past decade. That means that the amount of electricity, cooling and space per TB has halved in the past decade. So how much of an impact does this have on the monthly price per TB? Let’s do a bit of maths to find out. Feel free to change the parameters if you think I’m too far of:
Let’s say the price per TB is constant at around €20 per TB. Let’s further assume the lifetime of a disk drive is about 5 years before it is replaced. The price per TB per year would then be €4. That is a fixed price unless there is a new disk or flash technology that would significantly lower the price per TB in the next decade.
Now let’s have a look at power consumption: A disk drive uses about 10 Watts, independent of the capacity of the drive. Looking back a decade, one drive could store about 8 TB of data, i.e. 1,25 W per TB. In 24 hours and 365 days, that would be 10,9 kWh. At a price of €0.3 per kWh, that would be €3.27 power costs per TB. Add to that the price for cooling, let’s say 20% and you are at about €4 power costs per year per TB of storage. In addition, you need to add the costs of building and running a data center, cooling excluded. I have no idea how much that is, so let’s assume it is €2 per year per TB. So in total, the running cost would be €6 per TB per year.
Even for consumer grade storage, there has to be redundancy. So let’s say we have a redundancy factor of 1.5, so we multiply all costs with that factor. That means that a decade ago we had a hardware price per TB per year of €4 and a running cost per TB of €6 per year. That’s €10 per TB per year or about €0.83 per month.
Fast forward to today (2025) and the hardware price per TB is still €4 over 5 years. Running costs will be about half, as twice the amount of data now fits on a hard disk. So price per TB per year has decreased by 25%.
25% is better than nothing, but how much has the yearly amount of data per customer increased in this decade? For most applications it is likely that it is much more than just 25%. So the decrease in cost per TB per year is unlikely to make up for the additional amount of data that has accumulated in the meantime.
Which means: At some point we do have to throw away accumulated data because of the rising cost. Unless, of course, storage becomes cheaper. But as as far I can tell that is nowhere on the horizon.