What happens when you DON’T ‘Safely Remove’ your USB drive?

We’ve all been here before. You’re transferring a file from your Windows computer to your USB flash drive or external hard drive. Once the progress meter hits 100%, you just yank it out of the USB port. But all our lives, we know that the best practice for this, is to find the ‘Safely Remove Hardware’ or ‘Eject’ button in the task bar before removing our external media.

What is actually going on here? Why is it usually okay to do this? Should you ‘Safely Remove’ your USB drives?

Write Caching

First, we need to understand the concept of write caching. This is a feature in Windows that actually improves the performance of a drive by utilizing your system’s RAM to collect the write commands, cache the files, and then write them to the drive later on. It does, however, leave your files vulnerable to corruption because if the transfer is never completed due to loss of connection or power.

This is why write caching is enabled by default for your internal drives; they aren’t really going anywhere. Your computer is free to carry on its processing duties without being burdened by files moving around, hence the aforementioned improvement of performance.

Write caching is NOT turned on by default for removable drives, at least in Windows 10, for the same reasons. Instead of caching the files you want to transfer in the system’s RAM, files are immediately written to your external disk. As you can see in the removal policy options for external drives, ‘Quick removal’ is selected by default, and it actually states that “you can disconnect the device safely without using the Safely Remove Hardware notification icon.”

Reasons to Safely Remove

Assuming your file transfer completed and can be opened from within your external drive, then it’s probably okay to just yank it out. However, the ‘Safely Remove Hardware’ option can show you a pop-up that says the drive is still in use, and to close all programs before removing it.

At this point, it’s a matter of “better safe than sorry”, so if you aren’t fond of hitting ‘Safely Remove Hardware’, then the least you can do is close all programs or windows that directly involve your external drive.

TL;DR

So, is it safe to skip the ‘Safely Remove’ option altogether when your file transfer is done? — Theoretically, yes. Windows has your back on this one by having write caching turned off by default for external drives. When the transfer is done, it’s done — you can get going.

Should I use it anyway because it’s good practice? — Probably. The ‘Safely Remove’ option still gives you the added assurance that it’s actually safe —  no more programs are using your external drive, and you’re good to go.