As an experienced Mac technician, one of the most common issues I see is excessive wear on a computer‘s solid-state drive (SSD). SSDs offer lightning-fast performance compared to traditional hard disk drives, but they also have a limited lifespan. Every time you write data to an SSD, it experiences a tiny amount of wear. Over time, this adds up and can lead to slower performance, errors, data loss, and even complete drive failure.
This is especially a concern with newer MacBooks and Mac desktops that use Apple‘s custom M1 or M2 chips. These models have the SSD soldered directly to the logic board, making it expensive or impossible to replace. Shortly after the first M1 Macs launched in late 2020, many users reported alarmingly high rates of SSD wear that threatened the longevity of their machines.
Apple quietly addressed the worst of the issue with macOS updates, but SSD wear is still something every Mac user needs to be aware of and proactively manage. In this guide, I‘ll explain what causes SSD wear, show you how to check your drive‘s health, and share my top tips to keep your Mac‘s SSD in tip-top shape for years to come.
What Causes Excessive SSD Wear on Mac?
SSDs store data in flash memory cells that are organized into pages and blocks. Every time data is written to the drive, those cells experience a small amount of physical wear. Consumer-grade SSDs are typically rated for a few hundred terabytes written (TBW) before failure.
The lifespan of an SSD depends on a combination of factors, including:
Total bytes written: The more data that‘s written to the drive on a regular basis, the faster it will wear out. This is why it‘s important to monitor the cumulative data written to your drive over time.
Write amplification: Not all data written to an SSD is user data. The drive‘s controller also performs housekeeping tasks like garbage collection and wear leveling that generate additional write operations, known as write amplification. The higher the rate of write amplification, the more quickly cells will wear out.
Operating temperature: Flash memory cells can become unstable and wear out faster in extremely hot or cold environments. It‘s best to use your Mac in moderate, controlled temperatures.
Improper shutdowns: Suddenly losing power in the middle of a write operation can corrupt data and cause additional wear on the drive. Always shut down your Mac properly using the Apple menu.
Manufacturing defects: Not all SSDs are created equal. Lower quality drives may have more defective cells out of the box, leading to earlier failure. Stick with reputable brands like Samsung, Crucial, and Western Digital.
How to Check Your Mac‘s SSD Health
macOS includes a built-in utility to check the health and wear of your SSD. Here‘s how to access it:
- Click on the Apple menu and select "About This Mac."
- Click "System Report."
- In the sidebar, expand "Hardware" and click on "Storage."
- Select your built-in SSD in the main window.
- Look for the "SMART status" field at the bottom. It should say "Verified." If it says "Failing," your SSD is near the end of its life and you should immediately back up your data.
You can get more detailed wear level info by enabling the Terminal command sudo smartctl --all /dev/disk0. Look for "Media Wearout Indicator" in the output. A value of 100 means a brand new drive, while 0 means a completely worn out one.
I recommend checking your SSD‘s health and wear level every few months so you can monitor it over time and hopefully catch any issues early. If you notice the wear level dropping faster than expected, it‘s time to dig deeper and see what might be causing excessive wear on your drive.
10 Tips to Reduce SSD Wear and Extend Your Mac‘s Life
Now that you understand what causes SSD wear and how to check it, here are my top tips to minimize unnecessary wear and keep your Mac‘s drive healthier for longer:
1. Keep your software up to date
Apple regularly releases updates to macOS and pre-installed apps that can improve SSD performance and longevity. For example, macOS 11.4 and later include optimizations that address excessive SSD wear on M1 Macs. Staying up to date ensures you benefit from the latest improvements.
2. Optimize your storage
A nearly full SSD will generate more write amplification and wear than a less full one. Make a habit of removing old files and apps you no longer need to maintain ample free space on your drive, at least 10-20% of its total capacity. You can open up About This Mac > Storage to see a breakdown of how your disk space is being used.
3. Move files to an external drive
Consider moving large, infrequently accessed files like photos, videos, and archives to an external drive to reduce data on your internal SSD. You can keep the external drive connected most of the time for easy access, but this keeps your SSD free for more performance-critical files.
4. Adjust system settings
There are several advanced settings that can affect SSD wear:
- Disable hibernation to prevent the system writing gigabytes of memory contents to disk when sleeping.
- Turn off local Time Machine snapshots if you‘re backing up to an external drive anyway.
- Reduce the size of the RAM disk for sleep images.
- Make sure TRIM is enabled for optimized garbage collection (it should be by default).
5. Monitor drive health with smartmontools
The smartmontools utility gives you more advanced drive health information through Terminal, like the number of unsafe shutdowns, uncorrectable errors, and more. Enable it with brew install smartmontools and use smartctl -a disk0 to generate a report.
6. Avoid expose your Mac to extreme temperatures
Don‘t leave your Mac in a parked car on a hot day or use it outside in freezing temperatures. Heat is especially harmful to SSDs. Always use your computer in a temperature controlled environment.
7. Properly eject external drives
Yanking out an external drive without properly ejecting it first can occasionally cause drive corruption that may impact the internal SSD as well. Always eject your drives before physically disconnecting them.
8. Don‘t use your Mac while charging
The SSD can experience more wear when you‘re using your Mac while it‘s plugged in and charging, due to higher power usage and temperature. When possible, avoid heavy workloads until your Mac is fully charged and unplugged.
9. Use optimization and maintenance utilities
Apps like DriveDx, Disk Drill, Onyx, and CleanMyMac X offer additional features for checking SSD health, performing maintenance scripts, clearing out junk files, and more. Running these tools on a regular basis (e.g. monthly) can go a long way toward reducing SSD wear.
10. Consider a fresh install every few years
If your Mac is more than a few years old, reinstalling a clean copy of macOS can clear out cruft and restore your SSD to peak performance. Of course, always make a complete backup before attempting this. Then boot into Recovery mode, erase your drive with Disk Utility, and reinstall macOS. Finally, migrate your data back and reinstall apps selectively.
The Bottom Line
SSD wear is a fact of life, and all drives will fail eventually. But by implementing the tips above, you can significantly reduce unnecessary wear on your Mac‘s SSD and extend its lifespan to get the best return on your investment. The key is to be proactive about monitoring and maintaining your drive health before small issues turn into bigger problems.
If you do encounter signs of SSD failure, like frequent beach balls, system crashes, or corrupted files, don‘t ignore them. A failing SSD can cause data loss. Always maintain regular backups and be prepared to replace your drive if needed.
With proper care and feeding, your Mac‘s SSD should provide many years of blazing-fast, reliable storage. Stay on top of your drive health and enjoy the benefits of modern solid-state storage without wearing it out prematurely. Feel free to reach out in the comments if you have any other questions!