Hard drives are a key component in modern computers. It’s normal to purchase a new one every few years, either to replace an old hard drive or to use as an additional hard drive.
But with so many choices out there, which one is best for you? Which one should you buy?
The good news is that hard drive shopping isn’t all that difficult. In fact, there’s a lot of leeway for error here — as long as you follow these guidelines, you won’t have to worry about “buying the wrong hard drive” or anything like that.
Hard Disk Drive vs. Solid State Drive
The absolute first decision to make as far as data storage is concerned is whether or not you want a solid state drive (SSD). While an SSD fulfills the same function as a traditional hard disk drive (HDD), it has its own set of pros and cons.
For those who don’t know, an SSD is a type of drive that uses something called flash memory for storing data instead the spinning metal disks you’d find in a traditional HDD. Think of it like a massive USB thumb drive.
What difference does it make, anyway?
First, SSDs are faster at reading and writing data. Second, SSDs require less power draw which conserves energy and extends laptop battery life. Third, SSDs have no moving parts so they make no noise and have longer lifespans. The downside is that SSDs are more expensive and have smaller data capacities than HDDs.
What’s the bottom line? If price is a big concern, go with a traditional HDD. Or if you’re buying the drive mainly as a backup drive, go with a traditional HDD. And as far as HDDs are concerned, you can’t go wrong with the WD Blue 1 TB HDD which only costs $50.
But if the drive is going to run an operating system or hold a lot of frequently-accessed files and programs, especially video games, then go with an SSD instead. And as far as SSDs are concerned, you can’t go wrong with the Samsung 850 EVO 500 GB SSD which costs about $160 but performs well and lasts a long time.
Physical Size and Interface
Once you’ve decided between an HDD and SSD, you have to pick a form factor. Thankfully, there are only two choices and the right choice will mostly be dictated by your current setup. Don’t worry, this decision will be easy.
Data drives come in two form factors: the 3.5-inch drive and the 2.5-inch drive.
In traditional HDDs, data is stored on spinning metal disks, which means that more disks are needed for expanded data capacity. For this reason, desktop HDDs tend to be 3.5-inches with a maximum capacity of 4TB while laptop HDDs tend to be 2.5-inches with a max capacity of 2TB.
On the other hand, SSDs can be made smaller because they don’t require movable parts. As such, most SSDs fit the 2.5-inch form factor. However, if you need to fit an SSD into a 3.5-inch connector, there are adapters available.
As far as connections are concerned, most modern consumer drives — both HDD and SSD — use SATA connectors. Older HDDs that were created before the SATA standard will likely use IDE connectors instead. And if you’re buying an external drive, it will connect to your system through a USB port.
Note: Not sure what SATA, IDE, or USB mean? Check out our post on common computer cables to get up to speed.
Specifications and Performance
Now that you know what kind of drive to buy, it’s time to find the best one that fits your needs. Here’s what you need to consider.
Storage capacity. HDDs come in all sizes, capping out at 4TB per drive due to physical limitations. On the other hand, SSDs are much smaller and haven’t yet been able to break the 1TB mark. Even so, consumer-level SSDs rarely exceed 512GB.
Transfer speeds. The performance of a consumer-level HDD is determined by many factors, but revolutions per minute (RPMs) is an important one. Higher RPMs means faster transferring of data to and from the drive.
Also, ignore the drive’s SATA speed. For example, a modern drive might be listed as 3.0 GB/s and 7200 RPM. No HDD is ever going to be able to transfer data at speeds of 3.0 GB/s, but a 7200 RPM drive will always be faster than a 5400 RPM drive.
Cache space. When a hard disk needs to transfer data from one section of the drive to another, it utilizes a special area of embedded memory called the cache or buffer.
Larger cache will enable the data to be transferred faster (because more information can be stored at one time). Modern HDDs can have cache sizes ranging from 8 MB to 128 MB.
Access times. Traditional HDDs have a couple of other factors that impact performance, such as the time it takes for the reader to position itself to read data from or write data to the drive.
While it’s true that two 7200 RPM drives could have differing performances — e.g. one of them might be slower at repositioning the reader — there’s no standard way to compare access times. Plus, most hard drives perform at similar levels these days, so I wouldn’t worry too much about this particular detail.
For SSDs, you’ll want to look for sequential read and write speeds (also called sustained read and write speeds). As long as those speeds are within the SATA connector’s max speed, which they most likely will be, you should be fine.
Failure rate. Since HDDs are mechanical, wear and tear is expected over time; that being said, not all HDDs are made equal. Some models are prone to fail within 6 months while others have average lifespans that exceed 6 years. It’s your responsibility to research this on a per-model basis prior to making a purchase.
On the whole, according to StorageReview, modern SDDs tend to last longer (average failure rate of 2.0 million hours) than modern HDDs (average failure rate of 1.5 million hours). However, for long-term disconnected storage, HDDs are far more reliable than SSDs.
Are you worried about hard drive failure? Consider setting up RAID storage to keep your data protected against sudden and unforeseen malfunctions.
Based on all of the above, you’re going to run into a wide range of prices for hard drives that look very similar on the surface. It’s up to you to decide which factors are most relevant to your needs and to select a hard drive that fits those parameters. To determine value for money, divide the drive’s retail price by its storage to get a price per gigabyte.
For example, the WD Black 1 TB HDD ($70, $0.07/GB) is an all-around good purchase for the everyday consumer. However, bumping up the storage capacity to the WD Black 2 TB HDD ($125, $0.06/GB) will nearly double the price. Bumping up the capacity again for the WD Black 4 TB HDD ($235, $0.05/GB) will cost you a pretty penny. Although it’s hard to swallow, the 4 TB drive offers the best value for money.
The trend is mirrored for solid state drives. The Samsung 850 EVO 250 GB SSD ($95, $0.38/GB) is affordable, but the Samsung 850 EVO 500 GB SSD ($157, $0.31/GB) grants twice the space for less than twice the price. And when you get up to the Samsung 850 EVO 1 TB SSD ($305, $0.30/GB) your wallet will start to sweat, but it offers the best bang for your buck.
And as you can tell, the HDDs offer a whole lot more space than the SSDs even though they progress at similar price points.
External vs. Internal
The final thing to consider is whether this hard drive is going to housed within the casing, or used externally. It’s an easy decision, but let’s take a look at the pros and cons of each.
External drives are perfect for storage and backups. They typically connect using a USB 2.0 cable which caps out at 480 Mb/s, though later models may support USB 3.0 which caps out at 5.0 Gb/s. Unless you can get one of the latter, the speed will likely be too slow for primary use (e.g. running an operating system).
The trade-off is that external drives are portable. They can be shared between multiple computers without any hassle. Just unplug the USB, plug it elsewhere, and you’re done. They can also be plugged into TVs and media centers for direct media playback.
If you need the speed, don’t need the portability, or if your system lacks a working data drive (e.g. if your last one malfunctioned and you need to replace it), then use it internally.
To clarify, any data drive can be used internally or externally as long as the connectors are compatible. When used externally, drives are simply encased in protective casings. If you bought an external drive, you can remove the actual drive and use it internally if you desire.
We recommend using HDDs for external drives because you rarely need the performance of an SSD for that, plus HDDs tend to hold up better over time. Just make sure you get one with USB 3.0 support, like the Seagate Expansion 1 TB Portable HDD which is very affordable at $55.
If you’re looking to maximize absolute capacity, then opt for the non-portable version called the Seagate Expansion 8 TB Desktop HDD which is pretty hefty at $230. However, you do get 8 TB of storage space, and if you think of that in TBs-per-dollar, it’s one of the best deals you’ll ever find.
But if data security is your primary concern, you may want to go with the Transcend 1 TB StoreJet M3 HDD which is competitively priced at $57. What’s so good about it? It comes with military-grade shock resistance, has an anti-shock rubber case, an internal suspension system that can survive drops, and built-in 256-bit AES encryption.
All that being said, if speed is of utmost importance and you don’t have that much data to store, then an external SSD might actually be preferable. These are rarer than external HDDs so pickings are slimmer, but good options exist — like the Samsung T3 500 GB Portable SSD which costs $170. Just make sure to use a USB 3.1 cable otherwise you won’t get the full transfer speed.
Wrapping It All Up
Now you know all there is to know about buying a new hard drive. Once purchased, be sure to take care of your hard drive properly in order to extend its lifespan and keep it clean with these hard drive organization tips.
Do you have any spare hard drives lying around? Don’t throw them away! Here are some neat ways to breathe new life into old hard drives. Wring some more value out of them!
Have any questions? Got any other hard drive buying tips to throw into the mix? Share your thoughts with us in the comments below!
Image Credits: Portable Drive Stack Via Shutterstock, SSD vs. HDD Via Shutterstock, Form Factor Comparison Via Shutterstock, Open Hard Drive Via Shutterstock, SSD Diagram Via Shutterstock, External Hard Drive Via Shutterstock