Although the internal storage of a PC or laptop may be large enough for many users, some people will inevitably need extra storage space and the portability which an external hard drive can provide. In this guide we’ll attempt to determine just how much storage you might need.
Types of external hard drive
Although this guide is geared towards helping you choose exactly what size external hard drive you need, it’s worth quickly running over the types available. There are two main kinds of external hard drives:
Hard Disk Drive (HDD)
HDDs have traditionally dominated the PC storage market, especially once they began to hold more data than writable DVDs. They work on a principle of magnetism: a rotating platter, which stores the data, is then interpreted by a read/write head.
HDDs definitely give you the most storage for your money, though the read/write speed is nowhere near as fast as that of the SSD.
Solid State Drive (SSD)
Although technically not a hard drive, an SSD fulfils the same purpose. An SSD has no moving parts: the data is stored in integrated circuits rather than rotating platters, which explains the SSD’s large speed advantage over the comparatively sluggish HDD.
A typical SSD has a file copy/write speed that’s at least double that of most HDDs – up to ten times as fast for the most advanced devices. This speed comes at a price: a typical SSD is much more expensive than an equivalent HDD.
Unless you need especially fast access, for example if you’re working with resource-intensive graphics or audio applications, an HDD is probably the way to go for your external storage.
Connectivity of external hard drives
It’s also important to consider the various connectivity options available on today’s external hard drives. Although the vast majority connect via a form of USB, some drives contain features which you might not be able to take advantage of.
A USB 3 hard drive will typically work fine when plugged in to a USB 2 port, but you’ll be stuck at USB 2 speed. Some devices may also connect via Firewire or Thunderbolt only, though these are few and far between nowadays.
Physical size / portability of external hard drives
As well as storage space, you should also take into account the physical size of the external hard drive. Physically smaller hard drives will tend to be more expensive, especially at higher storage capacities, but this might be a price worth paying if portability is an important factor.
Hard drive storage is typically measured in gigabytes (GB) or terabytes (TB). There are 1,000 megabytes (MB) in a gigabyte, and 1,000 gigabytes in a terabyte.
What size external hard drives are available?
The smallest external hard drives on the market today tend to hold around 128GB. Others hold 10TB – an almost 10,000 percent difference! Of course, almost every size in between is represented, so you can be sure there’ll be something to suit your needs. However, the most popular capacity is 1TB or 2TB. And, if you’re undecided you won’t go far wrong with a 1TB hard drive.
Typical size of common file types
Although a file of any given type can vary wildly in size, here are some typical sizes of various file types:
• Microsoft Word document: 0.3MB
• Music (128 kbps mp3): 4MB per song
• Music (320 kbps mp3): 10MB per song
• Music (lossless FLAC): 20MB per song
• 3 megapixel JPEG image: 0.5MB
• 15 megapixel JPEG image: 4.5MB
• 3 megapixel TIF image (uncompressed): 9.2MB
• 15 megapixel TIF image (uncompressed): 44.1MB
• Standard Definition video for viewing, 1 hour: 280MB
• High Definition video for viewing, 1 hour: 440MB
• Standard Definition, compressed video for editing, 5 minutes: 1GB
• High Definition, uncompressed video for editing, 5 minutes: 45GB
As you can see, the amount of space you’ll need on your external hard drive will vary massively depending on what kinds of files you need to store on it.
It’s clear that you won’t need much more than the 500GB if you’re mostly storing documents with maybe the odd photo album or wedding video, but your needs will increase if you’re storing a lot of larger files – lossless music or TV box sets, for example.
If you’re working on music, photography or, especially, video production, you’ll want an external hard drive with as much capacity as possible.
What size external hard drive do I need?
Of course every case is different, but the list below should give you some idea of the average external hard drive needed, depending on what kinds of files will take up most of your storage:
Music (compressed): 256GB
Music (lossless): 500GB
Music (production): 1TB-4TB
Photographs/images (casual): 100GB – 1TB
Photographs/images (professional/editing): 1TB+
Videos (SD/casual): 1TB-2TB
Videos (HD): 2TB-4TB+
Videos (production/editing): 4TB+
Price vs storage
Storage is relatively cheap these days. Often, at the lower end of the price range, it doesn’t cost that much more to double or even quadruple the storage available. For a 1TB external hard drive you’re looking at less than £50. Which is incredible value for money.
If you’re undecided between two models of different size, it’s probably a smart idea to choose the larger hard drive. After all, that extra space won’t be doing any harm, and it could come in handy in the long run if your storage needs expand.
Ultimately, if long term storage is what you need, consider a larger but relatively cheaper external HDD. For working professionals or where speed is a priority, an SSD is the way forward.