You like to hibernate your PC every day when you’re done using it, but you’re worried that hibernating it puts excessive wear and tear on your SSD. Does it matter, or is it nothing to worry about? We crunched the numbers, so you don’t have to.
What Is Hibernation?
First, let’s talk about what hibernation is exactly. If we’re going to discuss whether or not it’s bad for your solid-state drive (SSD), we need to pick apart how it works.
When you’re done using your computer, you have a few options. You can just leave it running. Most people don’t do that unless they use their PC as a media server, torrent box, or another task that necessitates leaving it on. The exact opposite is completely powering it down for the day by shutting it down.
Historically, many people avoided that option because mechanical hard drives (HDDs) have long boot times, and they didn’t want to wait for the boot cycle and startup to finish the next time they needed to use their computer. Also, it’s really nice to pick up right where you left off with all your tabs open, your workflow in place, and such. That makes the other options, sleep or hibernation, much more appealing than fully shutting down your PC.
Sleep mode parks the computer state (open apps, documents, etc.) in the RAM and puts the computer in low power mode. Hibernation is similar, but instead, the contents of the memory are written to disk, and the computer enters a power state that is effectively identical to being turned off.
Sleep mode used to be preferable if you wanted a speedy return to your workflow, but modern computers are so fast now that it’s hard to tell the difference between waking up a computer that was in sleep mode versus one that was fully hibernated.
Why Do People Care About Hibernation on SSDs (But Not HDDs)?
Why are people curious about hibernation mode and SSD wear and tear but not with HDDs? The crux of the “Is hibernation bad for SSDs?” issue is the RAM-dump-to-disk write activity every time you put your computer in hibernation mode.
All disk activity puts wear and tear on the disk, whether a mechanical hard drive or a flash-based SSD. But disk writes to an SSD create a different kind of wear. A few metrics determine the longevity of an SSD, but a prominent one (and the one most relevant to our discussion) is the Terabytes Written (TBW) rating for the drive.
The TBW rating is the manufacturer’s way of quantifying the durability of the drive. Your SSD won’t immediately burst into flames if you exceed the TBW rating, but it’s worth retiring a drive (or downgrading it to a non-mission critical task) if it meets or exceeds the TBW rating.
How Much Wear and Tear Does Hibernating Put On an SSD?
You can’t avoid putting wear and tear on your SSD, because wear and tear is a side effect of just using your computer. But how much extra does hibernation contribute?
We can’t tell you exactly how much wear and tear it puts on your specific drive because the extra SSD drive writes are based on how much RAM you have, how utilized that RAM is, and the frequency with which you hibernate your PC.
But we can give you some general estimates and tips for calculating it yourself. Let’s use my daily driver Windows desktop PC as an example case.
It’s pretty common for a Windows PC to use around 50% of the available RAM as a baseline for just keeping the OS and basic day-to-day apps open, but you can always keep an eye on Task Manager to see what percentage your PC uses. On an average workday, mine fluctuates between 50-60%, as seen in the Task Manager screenshot below. You’ll likely find a similar figure in your own Task Manager.
You can calculate how much actual RAM is being used by dividing the percent in the memory column by one hundred and then multiplying it by the total RAM in your system. In my case, the system has 32GB of RAM, so the equation looks like (57/100)*32GB = 18.24GB.
If you don’t know how much RAM you system has, or you want a shortcut to get to the same answer we manually calculated above, you can check out the Performance tab in the Windows Task Manager. It’ll tell you how much RAM you have and how much RAM is currently utilized.
The RAM utilization fluctuated a small amount between screenshots, but you get the idea. The manual calculation and memory performance check both show my system is using around half the available RAM.
Once you have the value, in my case about 18GB, you have one last step. You need to multiply the value by 0.75. That’s because since Windows 7, when Windows writes the hibernation data to disk, it applies a compression algorithm that reduces the file size. So our 18GB or so of RAM utilization gets mashed down to about 13.5GB before it’s written to your disk.
So, on average, every time I hibernate my Windows PC, I write about 13.5GB of data to the SSD. If you have similar RAM utilization levels but only 16GB of RAM, you’ll likely write about 6-8GB of data per hibernation event when you account for the compression.
Want to double-check that under real-world conditions? The next time you bring your PC out of hibernation, check the file size of the hiberfil.sys file located on your C:\ drive. Our file is 13.39GB which lines up nicely with our estimated 13.5GB value.
Here’s Why It Doesn’t Really Matter That Much
The million-dollar question (or at least the $300 question if you’re trying to avoid replacing a premium SSD) is whether or not the extra writes matter.
Yes, it clearly adds wear and tear to the disk because you’re writing extra data every day that you wouldn’t otherwise write to the disk, but what does it mean relative to the lifespan of the disk? The quick answer: it doesn’t matter. But if you want the long answer, let’s crunch some numbers.
Again, I’ll use my daily driver machine to showcase things. I’m a great candidate for this showcase because I hibernate my PC daily like clockwork. Outside of occasionally using the “update and shutdown” option or shutting down the PC to swap parts or take photos for a tutorial, I always hibernate it.
If I load up CrystalDiskInfo, a tool we recommend in our guide to checking your HDD and SSD health, and check the Total Host Writes, the Power On Count, and the Power on Hours, I can get a sense of how much data is being written to the disk per day and what percentage of that data is from hibernation.
The Power On Count for the drive is 565. Power On Hours is 5,562. That makes sense to me. I built this particular PC about a year and a half ago, I use it almost every day, and if you divide 5,562 hours by 565 power ons, it works out to about 10 hours a day.
Some days, of course, I restart the computer because of an update or some such thing, but it’s safe to say that 565 is a pretty good stand-in for how many days I’ve used this drive (and thus how many times I’ve done a once-a-day hibernation).
If we multiply 565 by 13.5GB (the value for the memory utilization we established in the last section of the article) we get 7,627.5GB (or 7.63TB).
The Total Host Writes for the drive is 13,969GB (or 13.97TB). Divide the Total Host Writes by our estimation of how much data hibernation has written to the SSD, and you find that an estimated 55% of the disk usage to date is just from hibernation.
So you might react strongly to that and say, “Wait a second, you’re telling me that half of your disk use is just hibernation? Clearly, hibernation is terrible for your SSD!”
But hang on. Sure, that might seem surprising initially, but within the context of the drive’s TBW rating, it’s not such a big deal. The TBW rating for the drive we’re discussing here, the Western Digital Black SN750 1TB NVMe SSD, is 600TB.
After a year and a half of daily use, the drive is only 2.3% of its TBW rating. If I had never used the hibernation function, it would be 1.1% of its TBW rating.
At the current write rate (where I continue to hibernate at the end of each day), it will take me roughly 4.5 more years of use to get to 10% of the TBW rating. Even 10 years of use will hardly put a dent in the TBW. You’ll upgrade and replace your entire computer long before you even come close to exceeding the TBW rating.
In short, if you like using the hibernate function on your PC, keep using it and don’t even think twice about it. The level of wear and tear on an SSD created by writing the hibernation file to the disk every day (or even multiple times per day) is so small that it’s inconsequential over the lifespan of the disk.
