Installing an SSD in your PC, be it a laptop or a desktop, is one of the easiest and most effective ways to boost the machine’s overall performance. The change won't be merely noticeable—it will startle you. Your system will boot more quickly, windows and menus will jump open, and programs and data will load much, much faster.
In case you don’t know what an SSD is, the acronym stands for solid-state drive—that is,solid-state as in no moving parts, and drive as in the fact that an SSD appears as a hard drive to your computer. But instead of storing data on one or more spinning platters, an SSD writes and reads data to and from nonvolatile flash memory. In addition, an SSD contains a controller that's analogous to the memory controller in your PC’s CPU or core-logic chipset.
Many vendors sell SSDs, but the devices are far from equal. Flash memory and controller technology have both advanced so quickly that what was fast last year is now second-class. The drives you might find in the bargain bin will be faster than a consumer-grade mechanical hard drive, but they won't deliver the astounding performance boost you'll be looking for after you read this article.
To get the skinny on state-of-the-art consumer SSDs, we brought seven drives from five vendors into the PCWorld Labs and put them through the wringer. We tested Corsair’s Neutron and Neutron GTX drives; Kingston's HyperX 3K; OCZ's Vertex 4 and Vector drives; Samsung’s 840 Pro; and the SanDisk Extreme. We also retested Intel’s 240GB Series 335 SSD using our new benchmarking procedure (if you're curious, read our original review). Each drive delivers either 240GB or 256GB of storage, which is the current sweet spot in terms of price and performance. Each drive we tested proved to be a solid performer that will offer a significant boost over whatever conventional drive your machine has now. Some drives, however, are definitely faster than others.
If you’d like to upgrade a computer equipped with an older second-generation SATA interface (which maxes out at 3 gigbits per second), note that we also checked out theApricorn Velocity Solo x2, an add-in card that upgrades any computer with an available PCIe 2.0 x2 slot to the newer SATA 6-gbps standard.
But before we dive into those reviews, here’s a primer on SSDs that will tell you everything you need to know about this technology.
Controller
The memory/interface controller proved to be a major factor in determining each SSD's performance. Three of the drives we tested use a SandForce SF-2281 controller: the Kingston HyperX 3K, the SanDisk Extreme, and the Intel Series 335 (the controller firmware on this drive is tweaked to Intel’s specifications). OCZ’s Vector and Vertex 4 drives both use OCZ's proprietary IndiLinx controllers, namely the Everest 2 in the Vertex 4 and the Barefoot 3 in the Vector. Corsair is blazing a path with its Neutron series drives (the GTX and Neutron) by using Link A Media's LM87800 controller. Samsung's 840 Pro utilizes the company's proprietary MDX controller.
As you'll see in our performance chart, drives with the IndiLinx, Link A Media, and Samsung MDX controllers boasted significantly faster write speeds than the SandForce-based competition. In fact, counterintuitively, each of the five drives using those controllers wrote faster than they read. The SandForce-based drives were all good readers, but their comparatively slower write speeds dragged down their overall scores.
On the next page (scroll down past product-reviews for the link), I'll discuss memory types, interfaces, and how we measured performance.
Memory
Although the controller plays a big role in determining an SSD’s performance, the type of flash memory inside an SSD is also a huge factor. The SSDs in this roundup used either synchronous or toggle-mode NAND.
You might also encounter the terms SLC (single-level cell), MLC (multi-level cell), andTLC (triple-level cell) when researching SSDs. An SLC NAND cell has two states—on or off—so it can store one bit of data. An MLC NAND cell has two states besides off, so it can store two bits of data, while a TLC NAND cell has three states in addition to off and is therefore capable of storing three bits of data.
While MLC and TLC NAND deliver more capacity in the same physical space, they also bring a trade-off in performance and endurance. SLC NAND is faster and more durable than the other two types, but it’s also more expensive; you’ll find it today only in enterprise-level drives. Very few drives use TLC NAND, because it’s not as durable—it can’t handle as many program/erase cycles (which I’ll explain in a moment) as SLC and MLC can. Each of the drives in this roundup uses MLC NAND.
A note about endurance: All types of NAND flash memory have a limited life span. The MLC memory in consumer SSDs is good for 3000 to 10,000 P/E (program/erase) cycles, which is enough to deliver several years of normal usage. Unlike a mechanical hard drive, an SSD cannot simply write (program) data on top of old data that’s no longer needed; once flash memory has been written to, it must be erased before it can be written to again. Newer SSDs running on modern operating systems (including Windows 7, Windows 8, Mac OS X 10.6.8, and Linux kernel 2.6.28) use the TRIM command (it’s not an acronym, despite the caps) to actively inform the SSD controller of memory cells that contain unneeded data, so the controller can proactively erase those cells and make them available for storage once again.
So how long should you expect an SSD to last? The manufacturers’ warranties provide a clue: Both of OCZ’s drives, Corsair’s Neutron drives, and Samsung's 840 Pro drives carry a five-year warranty; the rest of the drives we reviewed are warrantied for three years.
Interface
To take full advantage of a state-of-the-art SSD (that is, one with a third-generation SATA 6-gbps interface), and get close to the speeds you'll see in our benchmark charts, you’ll need a motherboard with a third-generation SATA 6-gbps interface.
While mechanical hard drives don’t come close to saturating the second-generation SATA 3-gbps bus, the latest SSDs are already bumping up the against the limit of third-gen SATA. If you're adding an SSD to a laptop that has only a SATA 3-gbps interface, save yourself some money and go middle of the road—you’ll get very little benefit out of connecting a SATA 6-gbps drive to the older interface. If you're upgrading to an SSD on a desktop that has only a SATA 3-gbps interface, buy either a SATA 6-gbps controller card or a SATA 6-gbps piggyback card, such as the Apricorn Velocity Solo x2 (read our review). Under any circumstance, buy a top performer, and in the future you can transfer it into a better system to realize its full potential.
Performance
We evaluated the SSDs with a series of real-world data-transfer tests (by "real world," we mean a commonplace selection of data). Each drive was required to read and write both a 10GB mix of smaller files and folders and a single large 10GB file. To see just how fast the drives could go, we utilized a 16GB RAM disk to avoid any bottlenecks or interaction issues that a hard drive or second SSD might cause.
Our test bed consisted of an Asus P8Z77-V Pro/Thunderbolt motherboard, an Intel Core i7-2600K CPU, and 32GB of Corsair Vengeance 1600MHz DDR3 memory. The operating system was Microsoft Windows 8 (64-bit).