How To Build A PC

Step 6: Select Storage

The price per GB of storage for solid-state drives (SSDs) has been falling steadily over the past few years and has finally reached a point at which even those on tight budgets can afford one. While an SSD won’t actually make any of your processing-bound workloads run any faster, the vast reduction in the time it takes for applications to load and files to transfer provides a night and day difference in speed compared to the older mechanical hard drives (HDDs). Furthermore, now that SATA 3 drives have all but replaced their older SATA 2 counterparts, almost any cheap SATA SSD made by a reputable manufacturer will deliver superb performance.

Still, even with ever increasing capacities and with prices falling as low as they are, SSDs have yet to replace mechanical hard drives as a cheap solution for storing large amounts of data. Fortunately, 1TB mechanical disks start at around $50, which makes an SSD / HDD combo affordable for most builders unless you’re on a shoestring budget.

As far as SSD capacity goes, it depends on what you’ll be using your computer for and how much money you have. On the low end, a 120 GB SSD will offer enough room for a full Windows installation as well as enough room for handful of popular applications like Microsoft Office and Adobe’s Creative Cloud. A bit more money will get you to the 256 GB range, which should be enough room to store a modest number of games along with all of the other applications. 500 GB and 1 TB SSDs are also great options if you can afford them, and depending on your needs, may bypass the need for an extra mechanical hard drive altogether.

Interface wise, SATA is still the most popular for desktop storage, although other formats like SATA Express and various flavors of M.2 are quickly gaining in popularity and market share. Traditional SATA drives, while cheap and easy to come by are limited to SATA’s 6Gb/s maximum throughput, which has a practical transfer rate ceiling of around 550 MB/s. Meanwhile, the newer and more expensive PCIe based interfaces like SATA Express and M.2 have theoretical limits of around 16Gb/s and 32Gb/s, though in practice speeds will likely be slower as resources are shared between all PCIe devices.

Finally, those who are looking for yet another way to speed up their drives, or keep their data safe should consider the benefits of using RAID. RAID stands for Redundant Array of Inexpensive Disks, a group of methods that allows data to be spread across several drives concurrently. Most enthusiast-class motherboards support at least RAID modes 0, 1, 0+1, and 5. Each array of disks appears to be a single disk to programs other than the RAID utility.

The possible use of RAID affects the number and capacity of drives selected, so a very brief description of these modes is in order:

  • Level 0 divides data into chunks that are spread across two or more drives at the same time, providing up to double the transfer rate (in the case of a two-drive config) and the combined capacity. Because of the way the data is divided, this mode is also referred to as "striping" by in-the-know storage gurus. The major drawback is that if a member drive fails, the array's data is lost.
  • Level 1 mirrors two or more drives so that if one fails, data can be recovered from the other. The major drawback is that because both drives (again, in a two-drive array) store the same data, available capacity doesn't increase.
  • RAID 0+1 allows four (or more) drives to be set up as a "mirrored" set of "striped" drives. In other words, it's a RAID 1 array composed of two RAID 0 arrays. If one striped set (RAID 0 array) fails, data can be retrieved from the other. Total capacity is still limited to that of one striped set.
  • RAID 5 creates parity bits for data recovery. Data and parity bits are distributed across all drives, increasing transfer rate, while sacrificing only the amount of space required to store the added parity bits (the capacity of one drive in the set).

Generating parity bits for RAID 5 requires processing, which means that RAID 5 enabled in software can hog resources, however this rarely poses an issue today thanks to the amount of computing power available in modern CPUs. Conversely, RAID Levels 0 and 1 generate little CPU overhead. Gamers with little regard for long-term data storage may choose RAID 0 for performance, and anyone with a significant amount of valuable data that lacks the extra drive required for RAID 5 may choose RAID 1.

If you’re still unsure which SSD is best for your needs, our Best SSDs column includes pricing and performance data for some of the best value and highest performing drives on the market. Additionally, our storage reviews include several articles that go into further detail concerning RAID modes, benefits and consequences.

MORE: Best SSDs For The Money
MORE: Latest Storage News

MORE: Storage in the Forums

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  • James_39
    Selecting the case is a bizarre thing to have in Step 1.Surely that would be best placed once all other components, including accessories, have been factored in? Otherwise you end up selecting components purely on the basis they fit in your case, not forgetting that some (most) cases don't support water cooling kits/pipes etc mentioned in Step 8.