This page looks at Portable External Hard Drives, which do not require an external power supply (as opposed to mains powered desktop external hard drives).
Who might want a Portable Hard Drive
The main reason for buying a Portable Hard Drive is the flexibility of carrying a small device that simply connects to any computer with a cable – yet offering very high capacity. The small size and simplicity of connection allows the user to be able to have their files with them nearly all the time.
Portable hard drives are best suited to people who use multiple computers in different locations on a regular basis.
Unfortunately the fact that people are carrying their ‘Main Files’ around on a protable device is the main weakness of this type of storage. Not the drive itself, but the fact that most people simply do not keep backups of those valuable files.
To use a portable hard drive correctly you really need to set up a backup system so that files are frequently (daily if you update files daily) copied to another computer.
All hard disks will fail, portable hard disks are more likley to fail compared to a disk that is installed inside a desktop or laptop computer, because it is more likely to be dropped and most do not have a cooling fan, thus prone to heat issues, particularly during heavy file transfer (particularly a megnetic disk) when large files are being written or read.
Who might not want a Portable Drive
In simple terms people who DO NOT use multiple computers in different locations on a regular basis.
The following is a list of negatives relating to portable hard disks, some of these will apply to a greater or lesser extent compared to a desktop external drive:
- More expensive per Mb
- Slower read / write speeds – platter rotation speed may be an indication of this
- Quicker failure rate – particularly for heavy use and due to occasional dropping
- Easier to steal or even loose.
Portable Hard Disk as an offsite backup device
A very sensible use of these portable disks is to take copies of important files from a desktop, laptop or server and remove the device offsite. This probably offers the cheapest form of offsite backup and is very practical, particularly if you purchase a device with a USB 3 or eSATAp interface due to the very fast read / write speeds. The downside of using this device for offsite backup is the fact that you are depending on a human to do regular backups and to actually take the device offsite. Note – computer requires same interface for fastest data transfer rates.
One popular solution is to use five portable disks, label them Mon to Fri, keep them all offsite and only bring in one each day for that days backup.
HDD vs SDD
Portable hard drives fit into two main categories:
Magnetic Drives HDD – inexpensive
Solid State Drives SSD – more costly
Magnetic Portable hard Drives
By far the most common type because you pay much less per MB of data storage. Just like a fixed disk on a desktop or laptop or a desktop external disk, data is stored by magnetising tiny parts of rotating metal platters with North or South. Technological developments have constantly increased disk capacity, reliability and speed of writing and reading data.
Portable Solid State Drive
Not very common due to the expense. The largest size available at time of writing is around 500gb and costs around 4 times the cost of a portable 2tb drive (thus 16 times the cost per MB stored). Data is stored on electronic chips that do not require power to store the data (unlike the similar RAM chips in your computer, which loose all data when power is removed)
Advantage of Portable SSD:
- Very small size – eg 3′ x 2.5′ x 0.7′ and weighing 2 oz
- More reliable – less efected by high data read / write, heat or dropping
- Very fast data transfer sppeds – most will have a minimum of USB, eSATAp or the latest 10Gbit/s Thunderbolt interface
Using Portable Drives for Video Editing
If you are considering a portable drive to be primarily used for video editing there are a few things you should consider:
- Buy a magnetic disk – SSD capacities are just not practical for modern media files.
- Try to buy a drive with a platter rotation speed of 7200 rpm, most are 5200 rom which results in slower read / write speeds
- High capacity – buy the largest capacity you can afford 2tb disks are quite affordable with 3tb getting cheaper.
- Interface – If buying new do not buy USB 2, buy a drive with a minimum of USB 3, Firewire 800 or Thunderbolt (MAC). However you will only be able to use the fast data transfer speeds if the computer you are connecting to has the same interface. USB 3 is the most popular interface and you should buy a device with USB 3 even if your current computer is only equipped with a USB 2 interface – as you may buy a new computer before you buy a new portable drive.