Ask LH: How Large Should My Portable Hard Drive Be?

Hi Lifehacker, I'm planning to build a new PC in ITX-form factor, so a lot of space for hard drives could be a problem. Instead I'm looking to buy a portable hard drive to do backups and storage. Can you give me advice on the capacity and what to avoid when looking at a portable hard drive? (It will be staying at home most of the time, so size isn't an issue). Thanks, Portable Backup

Photo: Shutterstock

Dear PB,

The short answer is, you can never have "too much" capacity — so buy the maximum you can afford. If you end up with more storage than you currently need, you can be rest assured that the remainder will fill up in short order.

As a general measuring stick, you can expect a single 90 minute HD movie to take up a few gigabytes of storage space, while a high-end video game can require as much as 40GB. If you're a fan of either entertainment form, you need to go large!

It sounds like you're after a semi-permanent desk fixture as opposed to something for frequent travel. You should therefore plump for a bulky model powered by its own PSU. These tend to come in higher capacities and are less expensive than sleeker USB-powered offerings; especially on a per-gigabyte basis. In other words, avoid SSDs and pocket hard drives that sacrifice capacity for speed and portability.

You should also ensure that your PC and chosen hard drive both support USB 3.0. This will speed up backups and general file transfers significantly.

It's also important to take hard drive reliability into consideration when making your purchase. The online backup service Backblaze recently analysed the failure rate of 25,000 hard drives supplied by Seagate, Hitachi and Western Digital. It found its Hitachi drives to be the most reliable, with an overall survival rate of 96.7 per cent over 36 months. On a per model basis, the Hitachi GST Deskstar range had the lowest failure rate; from 0.9 per cent to 1.1 per cent.

By contrast, Backblaze's Seagate drives suffered failure rates of between 3.8 per cent and 25.4 per cent, depending on the model. With that said, the majority of drives did survive for at least three years of heavy use, so it's more a case of lessening your chances of bad luck than avoiding shoddy products.

Another possibility is to run a Networked Attached Storage device, or NAS. These are central storage hubs that provide easy access to files on any computer on your network. Building a NAS system used to require at least a small amount of technical know-how, but these days most manufacturers provide streamlined options for beginner-friendly setups. For example, the latest Seagate NAS range come with an EasyNAS tool that can automatically array drives to match the user's preferences.

Another advantage of a NAS solution is that you can boost your capacity on the fly by adding or swapping out internal drives. This is also more cost-effective than splurging out on another external hard drive when storage is running low. You can find plenty of additions information on this area by following our NAS tag.

If any readers have their own HDD tips or brands to avoid, let PB know in the comments section below.

Cheers Lifehacker

Got your own question you want to put to Lifehacker? Send it using our contact form.


    Be wary of interference with wireless mice and keyboards due to the USB 3.0 though!

    Just built a nice mITX HTPC at home and to my dismay my wireless products are laggy and glitch whenever I plug my hard drive in.

    Just a note of caution if you intend on using wireless equipment.

      Same here. Built mine maybe 4-6 months ago but when I plug anything into the rear USB ports, my keyboard struggles. Not a huge deal for me but it's definitely a pain.

    There is definitely no such thing as too much hard drive space. I have three portable HDs with a total capacity of 2TB - two Seagate and one Western Digital. Have owned the two Seagate drives for almost four years and have had zero trouble with either - the Western Digital drive is roughly six months old and as yet have had no issues. Would definitely recommend either brand.

    Most mITX form factor cases can usually fit at least one 2.5" and one 3.5" drive (or 2 x 2.5" drives) inside unless you're going for something really compact. If you're gaming then you'll need to get an mITX case that can take a GPU card and the case will definitely have enough room for a couple of drives. If you are going for a really small and compact mITX case then adding an external drive will result in an increased footprint anyway so why not go for a slightly larger case to hold the drive that will probably result in a lower overall footprint compared to a separate PC and drive.

      My reason for this is that they're easily separable, as in if I want to move all of them, the case and the drives can be put in different packages. The reason for that is because I live in a rent room (I'm a uni student at the moment) so I need to be prepared to unexpectedly move around, and if that happens, I can just put all the drives in one bag/package along with smaller things, and the case can stay alone. Beside that, the other scenario would be if me and my friend want to share something (we work on similar projects), it's a no brainer that it'd be easier on a portable than through the slow internet for large data. That would be my main reasons going with this.

    The short answer is, you can never have “too much” capacity — so buy the maximum you can afford. If you end up with more storage than you currently need, you can be rest assured that the remainder will fill up in short order.
    ^^ THAT.

    It comes down to what you can afford at the time of purchase. Dont worry about the capacity first. If you can get a 2TB portable for $90 and a 1TB for $85, you know which one to get.

    I went through a similar dilemma a while back. Depends how valuable the data is. The problem with most portable USB3.0 drives is they use proprietary circuit boards. This means even the slightest failure of even just the USB connector renders your drive useless, as you can't pull it out of the enclosure and connect it to your PC or another enclosure. So at the very least find a drive that's removable as there's a much greater chance of restoring a failed drive. I was dumb enough to not have backed up for about a month, so ended up having to order in a new circuit board for mine which thankfully allowed me to recover all the data.

    After nearly losing a lot of valuable photos, I re-assessed my strategy and settled on one of these:

    It uses 2x standard size, user removable, WD Red drives, which are higher grade drive built for better reliability. Don't bother with the RAID options, RAID1 isn't for backups and there's still a chance of raid failure. Set it to JBOD mode, store your data on one drive, and back up to the other using whatever backup utility you want. I'm on mac so I use time machine to back up my laptop and the first drive, to the second backup drive.

    Hi Lifehacker and everyone,
    Thank you for your advice and suggestions, now I'll have a peace of mind to keep track for a portable hard drive to grab and run.

    I like to have a portable drive that's >= my computer's capacity so that I can have a complete backup on it. Eventually I'll probably replace it with a cloud backup, but I have limited Internet at the moment so for the moment this is my solution for an off-site, always available backup. I have a bag that I take with me everywhere that I keep it in.

Join the discussion!

Trending Stories Right Now