What is a USB disk for?
More disk space: There are several uses for a USB drive and one is to extend the storage of the computer. If it has a small internal drive that is nearly full, plugging in a USB drive can provide 1TB (1,000GB) or more of storage for your files.
It is not quite as simple as plugging in the drive and you must move files from the internal drive to the external one to free up space. Videos, photos and music can be moved quite easily and it frees up a lot of space on the internal drive.
Backups: If only one copy of a file exists, what happens if it is lost or corrupted? What if the computer breaks down? Some files are valuable and it would be disastrous if they were lost, so a backup is essential.
A USB drive makes a great backup device and it can store a copy of your files in case anything happens to the disk in your PC. All backup software is designed to use USB drives and you could use a free program like Backupper or even File History in Windows 10. See Supercharge File History backups in Windows with these tweaks and Backupper gives event driven backups for Windows PCs.
1 SSD vs HDD
For decades HDDs (hard disk drives) were used in computers and over time they became faster and their capacity increased. They are still common today, but the future lies with SSD (solid state drives), which are basically collections of memory chips. Not the sort of memory chips that forget everything when the power is switched off, but ones that retain everything.
SSDs are much faster than HDDs and the performance is astonishing. Programs load so much faster and run faster too. They are also small and require little power, which makes them good to use with laptops or for portable drives.
The downside of SSDs is that they cost more than HDDs and have a lower capacity. However, the price is falling and the capacity is rising. It is worth paying the extra cost of an SSD for the performance boost it gives the PC.
However, if you have a small budget and need a lot of storage space, then good old fashioned HDDs provide the most storage for your money.
2 USB 2 vs USB 3
Old PCs have USB 2 sockets, but recent models have USB 3. So what? Well, USB 3 is more than 10 times the speed of USB 2 and it makes a tremendous difference when using an external USB drive. USB 3 is amazingly fast and USB 2 is frustratingly slow.
Most USB drives on sale support USB 3 and are super fast when plugged into a PC with USB 3 sockets. The drive will work fine if the PC only has USB 2 sockets, but it will automatically slow down and work at USB 2 speed.
This means that you will not see the speed benefit of an SSD if your PC only has USB 2 sockets. You may as well get a big and cheap hard disk drive. An SSD would be worth it if you think you might change your PC soon, because the new one will come with one or more USB 3 sockets and the USB drive will fly as it switches automatically to USB 3 mode.
3 Beware of big disks
Old PCs place a limit of 2.2TB on the maximum size of a disk that they can access. If you buy a 3 or 4TB USB drive and plug it into an old PC, you may find you can access only the first 2.2TB. The drive manufacturer may have a solution to this, but don’t assume it.
If your PC is fairly new and came with 64-bit Windows 10 pre-installed then it will be fine with drives bigger than 2TB, but if you have an old Windows 7 PC you should buy drives no bigger than 2TB.
4 Mains vs portable
Some USB drives are designed to sit on the desktop next to the computer and get their power from the mains supply at a wall socket. Other USB drives are small, compact and get all the power they need from the PC through the USB cable.
Check whether the drive you are buying is mains powered or runs off the power from the PC’s USB socket. It is usually high capacity USB drives that are mains powered and smaller portable drives are USB powered.
One isn’t better than the other and it is mostly down to convenience. Do you need a small drive you can carry in a pocket or bag?
5 Security options
Some drives have encryption built in and this means that even if someone stole your USB drive or you lost it, they could not access the files on it. I recently looked at the diskAshur2 USB drive with built in hardware encryption, but there are other drives from other companies with hardware encryption.
Do you need encryption? Look for it in the feature list when buying a drive if you do.
6 Which format is best?
Drives can be formatted using the FAT filing system (there are several variations like exFAT) or NTFS. Small drives tend to be FAT formatted because it makes them compatible with Windows and Linux PCs and Apple Macs. It is a universally supported format that is very useful for drives that are used on different computers and operating systems.
NTFS formatted drives can only be used on Windows PCs, which is fine if you only have Windows PCs. It is also more robust and technically superior to FAT, so it is prefered. Whatever the format of the drive when you buy it, you can always reformat it with whatever filing system you need.