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Types of SSDs and Which Ones to Buy

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Photo: partitionwizard.com

By now it’s likely you’ve heard of Solid State Drives, or SSDs as a blazing fast storage drive to speed up old computers, or provide reliable uptime compared to their replacement, Hard Drives, or HDDs. But there are countless options available, so what is the best drive?

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There are several connector types that SSDs use to interface with a computer, including SATA, PCIe, M.2, U.2, mSATA, SATA Express, and even none, as some SSDs now come soldered to the board. For a consumer, the most common options are SATA and M.2. SATA is known as the old two-connector system that hard drives used, including a SATA Power and SATA data cable. SATA-based SSDs are best for older computers that lack newer SSD connector types and have only SATA connections. A great way to boost the speed of an older computer with a spinning hard drive is to clone the drive to an SSD, and replace the Hard Drive with an SSD, increasing the computer’s ability to read/write data, possibly by tenfold. However it should be noted that these SATA drives are capped at a maximum theoretical transfer speed of 600MB/s, whereas other un-bottlenecked SSDs have recently exceeded 3GB/s, nearly five times the SATA maximum. This means SATA-based SSDs cannot utilize the speed and efficiency of newer controllers such as NVMe.

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NVMe, or Non-Volatile Memory Express, is a new controller used to replace AHCI, or Advance Host Controller Interface. AHCI is the controller that Hard Drives traditionally use to interface between the SATA bus of a Hard Drive and the computer it is connected to. AHCI as a controller also provides a bottleneck to SSDs in the form of latency the same way the SATA bus provides a bandwidth bottleneck to an SSD. The AHCI controller was never intended for use with SSDs, where the NVMe controller was built specifically with SSDs only in mind. NVMe promises lower latency by operating with higher efficiency, working with Solid State’s parallelization abilities by being able to run more than two thousand times more commands to or from the drive than compared to a drive on the AHCI controller. To get the optimal performance out of an NVMe drive, make sure it uses PCIe (Peripheral Component Interconnect Express) as a bus which alleviates all the bottlenecks that would come with using SATA as a bus.

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If the latest and greatest speeds and efficiencies that come with an NVMe SSD is a must have, then there’s a couple things to keep in mind. First, make sure the computer receiving the drive has the M.2 connector type for that type of drive. Most consumer NVMe drives only support the M.2 “M” key (5 pins), which is the M.2 physical edge connector. SATA based SSDs use the “B” key (6 pins) but there are some connectors that feature “B + M” which can accept both a SATA and NVMe drive. Second, the computer needs to be compatible with supporting and booting to an NVMe drive. Many older computers and operating systems may not support booting to or even recognize an NVMe drive due to how new it is. Third, expect to pay a premium. The PCIe NVMe drives are the newest and greatest of the SSD consumer market, so cutting edge is top price. And finally, make sure an NVMe drive fits the usage case scenario. The performance improvement will only be seen with large read/writes to and from the drive or large amounts of small read/writes. Computers will boot faster, files will transfer and search faster, programs will boot faster, but it won’t make a Facebook page load any faster.

In conclusion, SSDs are quickly becoming ubiquitous in the computing world and for good reason. Their prices are plummeting, their speeds are unmatched, they’re smaller fitting into thinner systems, and they’re far less likely to fail, especially after a drop or shake of the device. If you have an old computer with slow loading times in need of a performance boost, a great speed-augmenting solution is to buy a SATA SSD. But if being cutting edge and speed is what is what you’re looking for, nothing that beats a PCIe NVMe M.2 drive.