A tale as old as time itself – you have downloaded your photos or work onto your USB drive, and now you simply want to move on with your life and remove it. If only it were that simple. Instead, you must press “Eject” before pulling out the USB, or a sharp message will pop up telling you the “disk was not ejected properly”, you have lost everything you ever saved and the world is about to end.
But do you really need to eject a USB drive before removing it?
The short answer is probably not, but you may expose yourself to a small amount of risk if you don’t.
In early iterations of Windows, copying data onto a USB involved write caching, in which a device does not immediately finish writing the data and instead caches some of it onto your computer’s memory to finish at a later time. This takes some of the load off of the slow USB (compared to the rapid computer RAM), instead of flooding the USB full of write commands, allowing applications to run faster without waiting for the USB drive to finish doing its thing.
However, this is the reason why the eject button exists. If you remove the USB before the computer’s memory releases these commands and completes the whole process, you may be left with a USB that has the data on it, but it isn’t readable. Your files may become corrupted, a phrase every college graduate dreads.
Luckily for us, Microsoft gave up trying to be most efficient and accepted the fact that most of us just yank out the USB when done, so write caching is almost always disabled by default on Windows 7 and later versions. In fact, Windows 10 has a "quick removal" feature which is now the default for any new drive you plug in. This keeps Windows from continuously writing to the flash drive. You should be sure to check, though, if you are an avid premature ejector, as some external drives have write caching enabled.
For most of us, simply waiting until it says “done”, or waiting a few seconds after it's finished, will be ample to make sure the data is safe.