Buying an SSD – What Should You Be Looking For?

So you’ve decided to buy an SSD (or solid-state drive)! Good for you. Very suave. SSDs have been the latest craze among PC owners seeking to enhance the overall performance and user experience of their current PCs. PC owners are attracted to the SSD’s promise of faster data access, lower power consumption, ruggedness, and its complete operational silence as compared to the rotating magnetic hard disk drives (HDDs) typically used today.

Just as SSDs have increased in popularity, so have the number of SSD providers and brands. There are easily more than 20 SSD providers offering a variety of form factors, capacities, system interfaces, and performance ratings, all targeted to specific platforms and specific markets. But how do you navigate through the perplexities of making the right choice and making sure you spend your money wisely? As you start shopping, whether you prefer checking out retail boxes at a local electronics store or looking at e-tailer offerings, what do you need to know and what features and merits should you rely on to make your purchase? Allow me the opportunity to help!

Know the Key Ingredients

Are all SSD’s the same? No. Just as with cars, the components and ingredients that go into making an SSD have a drastic effect on the end-product. While the following items will not necessarily make it onto an SSD’s retail box or on an e-tailer’s product description, you need to be familiar with the key ingredients that make up an SSD in order to make an informed purchase: the NAND memory components, the interface and memory controller, and the managing firmware of the SSD. These ingredients will determine the SSD’s capabilities and its performance. So, when you start shopping, do so with the knowledge that not all SSDs are created equal.

Decide on Capacity

Assuming you already know what you plan to do with your SSD, whether you want to use it in a dual-drive configuration or as an HDD replacement, you have to decide on a capacity. If your plan is to use the SSD in a dual-drive configuration (as a boot or OS drive), then you’ll do well to get an SSD with at least 40GB of storage, like the Intel® X25-V SATA SSD. This way, you’ll have adequate capacity for the Microsoft Windows 7 OS, a good chunk of your current applications, frequently used files, and the page file. You can then use your HDD to store your data files.

If you are replacing your old HDD, then you need to know two things: how much storage you really need, and how much money you’re willing to spend. Obviously, if you choose a larger capacity, you’ll need to be willing to spend some more cash.

Be aware of the Physical Dimensions of the Drive Currently Installed in your System

After you decide what capacity you need for your system, you should check whether or not your machine requires the standard 9.5 mm-thickness drive. Most SSDs are 7mm thick, so if yours requires the standard 9.5 mm, make sure your SSD comes with a spacer ring that increases its size.

Research the SSD’s Performance

SSDs are all about performance. This performance is typically specified by how well the SSD can access its data randomly or sequentially. Because certain data is inherently sequential (photos, music, and movies) and other data types are inherently random (applications, system log files, and OS files), there are different specifications for accessing each type of data. The random data read and write access performance is typically specified in IOPS (input/output operations per second). You should look for an SSD that has high IOPS for random data access performance – this will ensure that you have fast application launch times, faster user file access, and faster systems boots. Such advantages greatly enhance the user experience and limit how often you’ll see the dreaded “hourglass”. So what’s a “good” IOPS rating for random read performance? You should aim for a drive that can randomly read 4 Kbytes of data at a rate of up to 35,000 IOPS. Think about an SSD reading data in 4Kbyte chunks — the same way a cargo ship carries a specified payload back and forth between destination ports. A good random write specification is in the range of 6,500 to 9,000 IOPS at a minimum.

The sequential data read and write access performance is typically specified in MB/s (megabytes per second), which is a fitting way to measure sequential streams of data (as opposed to a random stream). Sequential read and write performance typically has less of a noticeable effect on performance. Sequential data access is limited by bus interfaces, protocols, devices such as USB 2.0, MPEG video and audio, and DVD optical devices. Such interfaces are limited by throughput capabilities and protocol specifications, so exceeding the sequential platform requirement does not necessarily enhance the user experience. So what kind of sequential performance should you look for when buying an SSD? A good sequential read performance is 250 MB/s. A 70MB/s to 100MB/s sequential write performance is adequate for most uses.

Know the SSD’s Power Consumption

There may be SSDs on the market that advertise higher random and sequential performance numbers, but that may be at the expense of power consumption. If you plan on buying an SSD for use in a laptop, you want an SSD that operates efficiently. This means an SSD that provides you with PC-caliber performance with the right balance of power conservation. You should look for an SSD with an idle power of ~75 mW (milliwatts) and a typical active power of ~150 mW with a peak power usage of 2.5 watts.

Check for TRIM Support

But what if you don’t want to spend the time browsing the web for specific statistics? What are the most important features to consider when buying an SSD? You’d really kick yourself if you bought one that didn’t support the TRIM command. This feature is important because it allows the OS to inform the SSD which data blocks are no longer needed and can truly be deleted. The TRIM feature essentially allows the SSD to do its background “house cleaning” in preparation to store new data. If an SSD does not have this feature, the SSD’s read and write performance can be severely hindered – it will essentially be trying to move in and clean house all at once. Not fun! Most new drives do in fact support the TRIM command, but this is one feature you’ll want to research before shopping.

Look for Warranty and Support Options

Finally, make sure the manufacturer of the SSD you choose provides a three-year warranty and on-line software tools that keep your SSD running at its best. Intel® X25-M, X25-E, or X25-V SATA SSD would all be smart and sophisticated choices. Good luck shopping, and don’t forget to check out Intel SSDs at Best Buy! Feel free to leave comments or questions.

One Response to Buying an SSD – What Should You Be Looking For?

  1. Michael Sinat says:

    Thanks for writing this article Scott. Clear, concise and very informative. I’ve purchased the Intel X25-M SATA SSD Generation 2 and am very pleased with it. I’m getting sequential read speeds of 258.2 MB/s and writes of 107.8 MB/s. If you’re installing Windows 7 as most users will be, remember to set the BIOS to AHCI Mode as this will improve performance and also read the user guides and support from Intel before installing.