Storage is exciting. When was the last time you read those three words together? After many months of watching new SSDs slam into the SATA interface’s 6 Gb/s ceiling, PCI Express and NVMe are popping the cork and letting those IOPS flow freely. Of course, not all drives are created equal. A less-constrained bus means differences between controllers, flash technologies, and firmware maturity stand out.
You’ll have to pay particular attention to the nomenclature, too. Some M.2-based slots are wired to SATA; others connect to PCIe. From there, many motherboard vendors route their M.2 slots through the chipset’s slower second-gen lanes. More enthusiast-oriented implementations reserve a third-gen link to the CPU. And then there are the M.2 drives that drop onto an adapter card and plug into an available expansion slot.
That’s not to say vanilla 2.5-inch SATA-attached SSDs are suddenly boring. How quickly we forget what Windows feels like on a 7200rpm hard disk. No, today’s top solid-state drives offer more performance than most of us can use. They’re a lot less expensive than the premium PCIe-based stuff, too.
Don’t forget your hard drive. It remains the lowest level of any tiered desktop storage setup, providing plenty of capacity for not a lot of money. Dump movies, music, pictures, and documents on there—basically, anything that wouldn’t benefit from the speed of an SSD (and consequently doesn’t need to live on flash memory).
We’re in the midst of a storage revolution. While SATA-based SSDs are still plenty fast for most applications, 6Gb/s links are easily saturated nowadays. Enter Intel’s SSD 750 Series, designed to circumvent the bottlenecks imposed by previous-gen interfaces.
Solid-state storage relies on parallelization to maximize performance. You typically see controllers rocking four, eight, or even 10 channels over which they communicate with flash memory. Keeping those channels filled is how you get the biggest results. The latest processors have little trouble in this regard, and so it's common to see high-end drives posting benchmark numbers in the same range. This is largely attributable to SATA and the AHCI, the interface used to expose SATA’s features.
Intel’s SSD 750 family is held back by neither SATA nor AHCI. It sports a four-lane PCIe interface (that’s nearly 4GB/s of bi-directional throughput) and NVM Express support for more efficient access to information in a highly parallel architecture. Driving this point home is Intel’s 18-channel controller, a much more sophisticated piece of logic than anything previously available for desktop storage. Together, the new interfaces enable sequential reads up to 2.4 GB/s and writes as fast as 1.2 GB/s. Random 4KB reads crest at up to 440,000 IOPS, while reads are rated for a maximum of 290,000. Those figures can only be truly appreciated by someone who works in a data center by day.
This drive is bootable too, provided you have a Z97- or X99-based motherboard and an up-to-date BIOS. Expect to pay close to $1/GB for the very best in solid-state storage, regardless of whether you choose the entry-level 400GB model or the 1.2TB flagship.
It’s easy to bemoan the limitations of SATA when every high-end SSD can hit its ceiling. But in truth, most desktop workloads don’t come anywhere close to replicating synthetic benchmark results.
Samsung’s 850 EVO is supposed to be the company’s mainstream drive. Yet it offers more than 500 MB/s in sequential read and write operations. You can chalk some of that up to hardware—the 120, 250, and 500GB models employ a powerful MGX controller, while the 1TB version sports the MEX controller carried over from the 850 Pro. It’s partly innovation in software, too.
The 850 EVOs wield an improved version of TurboWrite, a firmware-based technology that sets aside a small amount of capacity to emulate super-fast single-level-cell memory, greatly accelerating write operations. You also get RAPID mode through Samsung’s SSD Magician utility, which leverages spare system memory for caching hot data, improving read speed.
Up and down the stack, Samsung uses its own 32-layer 3D V-NAND, enabling higher densities. The company claims its flash memory doubles the drive’s Total Bytes Written rating compared to the problematic 840 EVO, and backs its boast with a five-year warranty. Average power consumption lands in the four-watt range, though you can get down to the milliwatt level at idle thanks to DevSlp support. Best of all, the 1TB and 500GB models sells for around $.40/GB. Although faster drives exist, the 850 EVO is most certainly one of the smartest storage buys we’ve seen.
You’d be silly to build your storage subsystem using only SSDs. Solid-state space is perfect for operating systems, performance-sensitive apps, and games. But movies and music don’t play back any faster from an SSD. That’s why mechanical hard drives remain the right choice for your terabytes of user data.
Western Digital’s Black 4TB combines the best of performance, pricing, and protection. Its 7200 RPM spindle and dual processing cores can sustain up to 171 MB/s over a SATA 6Gb/s interface. A 64MB cache is controlled by an algorithm that balances between reads and writes in real-time, optimizing the fast memory for whatever workload is encountered.
Perhaps even more important than a few megabytes per second here or there (particularly for those of us already leaning on SSDs for performance) is long-term reliability. You should always be backing your data up somehow—be it to a RAID array, to an external drive, or to the cloud. But we still need to trust our storage devices. WD implements something called Vibration Control Technology on the Black family to compensate when the drives aren’t properly isolated from the rest of your chassis. Apparently it’s more than a gimmick, since the company takes a bold step in covering this family with a five-year warranty. It’s a shame we’ve had to grow accustomed to three-year coverage elsewhere in the hard drive market.
For around five cents per gigabyte, the 4TB model is a nice complement to any enthusiast-oriented machine. Just make sure you grab the Advanced Format-enabled model (WD4003FZEX), which is just a bit faster than its predecessor.
The storage market never slowed down, but SATA 6Gb/s sort of got in the way for a while there. Now, however, enthusiasts are being treated to a new class of PCIe-based devices that blow previous-gen SSDs away. Naturally, those drives are a lot more expensive (we’re back to $1/GB in a lot of cases).
Is the premium worth paying? If sequential reads in excess of 2GB/s matter to you, then yes. Otherwise, wait for the frenzy to subside a bit. More advanced manufacturing pushes down the price of solid-state storage. And once early adopters get their fill, the quickest M.2 drives will make a lot more sense. For now, take solace in the fact that most SATA-attached SSDs are plenty fast for desktops. You’re better off doubling down on capacity than chasing the last 1% of performance.