External Storage Devices

In this video from ITFreeTraining I will look at external storage devices. External storage has become more common for backup and to provide extra storage. This video will look at the different types that are available.

Internal Vs External
To start with, I will first look at the differences between internal and external storage. Internal storage is essentially connected to the computer via an internal connector. That is, a connector inside the computer that is not accessible from the outside. You can see in this example an M.2 Solid-State Drive used as internal storage. You can also see this hard disk is an example of internal storage although it is not physically mounted inside a computer case. The point being, if the connector is inside the computer and not accessible from the outside, it is considered internal storage.

Internal storage is generally faster and less likely to support hot-swapping. The advantage of it being inside the computer is it is less likely to be accidently unplugged.

By contrast, external storage is connected to the computer using an external connector. These will be found generally in the IO area or an external port like a USB, eSATA or Thunderbolt connector. These connections are generally slower, although new connections like USB 3 and Thunderbolt are pretty fast.

The advantage of external connectors is they are generally hot-swappable. That is, you can plug and unplug them without having to shut down the computer. The disadvantage is that they are easy to accidentally unplug. Since they are external to the computer, they are more subject to being bumped and a connection breaking. The connections are generally more prone to coming loose. For example, once you screw in an M.2 Solid-State Drive it is not coming out; however, a USB connection can come loose from either being knocked or pulled. So, let’s have a look at when you would use an external storage device.

External Storage
One of the common reasons to use external storage is to increase the data capacity of a computer. For example, if you have a lot of video files, a common method of storing these would be to use external storage. You could of course install an extra storage device inside the computer, however, in some cases it is easier just to plug in an external storage device. This is also an option if the computer does not support any additional internal storage devices.

The next common use is for backups. External storage devices don’t cost that much nowadays. Purchasing one is an easy way to back up your data. You can use the backup software that comes with the operating system or simply copy the files you don’t want to use onto the storage device.

External storage is useful in that it is very portable. This makes it easy to transport the storage between different computers. This also makes it useful for transferring data between computers.

What kind of external storage you purchase will determine how you will connect it to your computer. Some are essentially enclosures and will require power in order to operate. This makes them a little harder to use since you have to plug the power cable in as well as the data cable.

References
“The Official CompTIA A+ Core Study Guide (Exam 220-1001)” Chapter 6 Paragraph 261-266

Credits

[arthurswart]

Good and to the point. Mentioning there are SATA and NVME M.2 drives and enclosures that are incompatible (unless the are multi-keyed) will probably save some viewers an unpleasant surprise. A lot of older devices use Firewire, which is still a very usable protocol. Especially the ability to daisy chain Firewire devices is extremely handy. Finally I would have mentioned the existence of SAS harddisks, that are incompatible with SATA enclosures. In a system that supports SAS drives, both SAS and SATA drives can be used.
Besides eSATA, there is also aSATAp, which delivers 5V and 12V power together with the SATA protocol. I can not recall ever having come across an external device using either protocol. To be honest, I think it became obsolete before it became available. It's marginally faster than USB 3.0 (6Gbps vs 5Gbps), but neither connection will ever run at those maximum speeds.

An external 7200rpm mechanical SATA drive using eSATA, USB 2.0/3.0/3.1/3.1.2, Firewire 400/800 or Thunderbolt 1/2/3/4 will top out at about 150Mbps, about 1/3 of the speed USB2.0 is capable of. Usually this type of drive won't transfer faster than about 70Mbps. An external 2.5" SATA-3 SSD could reach 560Mbps, only barely faster than the 480Mbps USB 2.0 offers. In almost every use case, this drive will perform around the 350Mbps mark. Not all SATA SSDs are SATA-3, the cheaper drives up to 512Gb are sometimes SATA-2 and offer about 200Mbps using any of the mentioned protocols. Only when using an external NVME Gen3/4/5 in the correct enclosure, any of the protocols faster than USB2.0 speed things up.

With all of these numbers, you should ask yourself how much it really matters on a day to day basis. Would your day be better because you transferred a file in 22 seconds in stead if in 34 seconds? Unless you move huge amounts of data all day, you'll probably never notice that the drive only moves 100Mbps. The faster drives get, the less you will notice speed differences. A Gen3 NVME drive moves up to 1Gbps per (between 1-4) PCIe-lane(s), a Gen4 NVME drive is up to twice as fast. Only when you constantly move terabytes, that difference is noticable. For day to day office use, gaming, watching a movie or uploading your backup to your cloud drive, you will almost never be able to tell the difference between a 2.5" SATA-2 SSD or an M.2 NVME Gen4 drive.

I know Firewire is seen as obsolete, but buyers of low cost systems often find a FW400/800 (sometimes called 1394 to avoid the Apple royalty fee) among the I/O connectors. Not too fair sellers of used storage 'overlook' to mention a SAS drive doesn't work (or even fits) in most consumer systems. That cheap drive than turns out not to be the bargain it seemed to be. It happens with ECC memory as well.

[jerichochee]

Externally great, as well as all material on the inside (don't sue me)

[charalamposmpougatsias]

could you please upload a video about the correct cable management of a Desktop workstation pc?