If you actively follow the PC space for updates related to the latest hardware, you would be familiar with SSD (Solid State Drive) and can accord with the fact that of late, it has become one of the crucial factors when building a custom PC or deciding a laptop. For, in machines with even top-of-the-line specifications, a slow storage device, which in most cases happens to be HDD (Hard Disk Drive), can create a bottleneck and affect the overall performance.
However, if you belong to the other half of the spectrum, and are not well-acquainted with SSD, here’s a comprehensive SSD buying guide to help you make an informed decision.
For those unfamiliar with SSDs, here’s a quick primer: an SSD or Solid State Drive is a storage device, available as both internal and external drive, which allows you to store and manage data with faster read and write speeds. It provides quick access to onboard programs with faster loading speeds and offers a better overall experience when running multiple programs simultaneously. Moreover, if you install the operating system on an SSD, you can expect to get much faster boot times, and in turn, get the most of the powerful hardware sitting in your machine. Heck, you can even throw-in an SSD in an old computer to breathe life into it and get it to work manifolds better.
Compared to a regular storage drive or HDD, which comprises mechanical components that tend to age over time and are prone to discrepancies, an SSD, on the other hand, does not have any mechanical (moving) parts. Rather, it is a flash storage device that typically comprises NAND flash memory, much like thumb drives or memory cards. As a result, by not having a physical platter and other related hardware components (actuator, spindle motor, etc), an SSD also cuts down on the power consumption and even offers a relatively better service life. Although, since the technology used here is newer and advanced than the old, traditional HDD, SSDs tend to be a lot more expensive than their HDD counterparts.
Further, depending on the use-case scenario, there are different kinds of SSDs available in the market. Not to mention a wide range of brands, with each promising to offer some advantage over its competition — that adds to the confusion. So to simplify this equation, here’s a breakdown of the things you need to keep in mind when buying an SSD.
I. Different SSD Form Factors
The form factor describes the physical attributes of a device/hardware component, such as its weight, dimension, and other similar attributes. When it comes to SSDs, the underlying technology has seen significant advancements over the years, in terms of both performance and form factor. As a result, today, an SSD can be classified into four form factors.
The 2.5-inch form factor is reminiscent of the traditional HDDs found on a majority of machines. Colloquially referred to as small form factor (SFF), the name, 2.5-inch, indicates the drive measurement. It is a commonly used SSD form factor, particularly on machines that come with a drive bay and connect over the SATA (Serial Advanced Technology Attachment) interface. Since a lot of custom builds already happen to use the 2.5-inch HDD, the availability of an equivalent SSD counterpart makes the transition to a faster driver simpler, without requiring any extra hardware. Thus, making the 2.5-inch form factor one of the standards and most preferred choices for SSD.
M.2, erstwhile NGFF (New Generation Form Factor), replaces the mSATA standard. It is a relatively new specification for internally-mounted SSDs. The module appears similar to a RAM stick and finds its applications across a majority of laptops these days. Not to mention, it is also being increasingly adopted by various motherboard manufacturers. The M.2 SSDs come in different sizes and have the NAND chips present on either one or both sides. For instance, in the case of soldered-down modules, the chips are only located on one side, as opposed to swappable modules, that can have chips present on both sides. Further, it is upon the manufacturer to decide which interface to provide on its drives — which again depends on a bunch of factors. In general, you can find an M.2 SSD with either SATA or PCIe interface, with the ones having PCIe interface carrying a higher price tag.
From the looks of it, U.2 SSDs appear somewhat identical to the SATA HDDs from back in the day. They come in at 2.5-inch, which is comparatively bigger than M.2 SSDs, and therefore, offer more capacity and better heat dissipation than M.2. When it comes to connection type, U.2 utilizes the PCIe interface for establishing connection with the motherboard. However, it requires a separate connector, similar to the SATA Express plug, if you wish to connect it to an M.2 port. One of the advantages that U.2 holds over M.2 is that it supports hot-swapping — meaning, you can replace or add the SSD while the machine is running, without having to shut down/restart it.
4. Add-in card (AIC)
An Add-in Card (AIC), as the name implies, is a form factor that offers the ability to plug-in an SSD to a machine like an extension. Thus, offering more compatibility and flexibility. It relies on the PCIe expansion slot for connection, which also happens to provide it an advantage — as for those who own an older machine with a relatively old motherboard, it is likely that it won’t have a modern interface (like M.2). So for such instances, the add-in card (AIC) form factor is a godsend and makes it easier to upgrade a machine with a faster storage component. However, if you happen to have a graphics card installed on your machine, it may not be possible to add an AIC SSD since the two use the same slot. Also, as of today, these SSDs are not the preferred choice for an average user and are mostly preferred by hardcore enthusiasts — mostly for aesthetic purposes.
II. Types of SSD Interfaces
In much the same way as the SSDs have various form factors, the technology has also seen advancements and improvements in the way it communicates with the motherboard, ie the interface. From SATA-connection drives that date back to the old times of HDD, to the PCIe ones with NVMe support, there are various types of interfaces, used by SSDs. Here’s a breakdown to simplify this.
The most common interface used by a majority of consumer-grade SSDs is SATA or Serial ATA (Advanced Technology Attachment) — particularly the SATA 3.0. It has been around for a long time now and has been a preferred choice for data transfer between motherboard and storage devices, like the HDD and optical drives from back in the day. One of the added advantages of the SATA interface is that it can automatically check the transmission instructions and correct an error in case it finds one. Thus, being more reliable in data transmission.
Talking about the transmission speeds, SATA 3.0, which is the preferred SATA interface choice for SSDs, offers a maximum transfer speed of 6Gbps — two times that of SATA 2.0. Although, due to certain hardware limitations, the actual speeds usually tend to be lower, unless, of course, the drive and the interface are both compatible and support high-speed transfers. Besides, it is also worth mentioning that there is also the host controller interface, AHCI (Advanced Host Controller Interface) in case of SATA, which was ideally designed for mechanical drives and could, therefore, cause some kind of bottleneck. [For those unaware, besides the interface, which is used to connect a driver, there is also the need for a protocol that can aid with establishing connection between the motherboard and the drive]. Besides, from what it appears, SATA 3.0 (and AHCI) seems to have peaked in terms of the transfer speeds and overall performance, which is why most high-end users gravitate more towards other interface options.
M.2 is one of the most common SSD interfaces out there. It is widely adopted by manufacturers and can be found on PCs, laptops, and notebooks. The interface was developed by Intel as a replacement for mSATA (Mini-SATA), which has become obsolete in the current times. Compared to mSATA, M.2 offers faster speeds and more volume — something that has increasingly become one of the crucial deciding factors when it comes to SSD. Moreover, another factor that makes M.2 better over its predecessor is the efficiency, with faster speeds on a relatively smaller footprint.
The smaller footprint makes the M.2 interface a preferred interface of choice on laptops and notebooks. Similarly, it also allows for multiple interfaces on a motherboard, which can help those who need to have multiple SSDs running in RAID configuration.
PCIe (Peripheral Component Interconnect Express) is a standard connection type for various internal devices and has started seeing an increase in adoption in recent times. It is also one of the preferred SSD interface choices as compared to SATA (SATA 3.0, in particular) primarily due to higher transfer speeds — 1Gbps over 600Mbps. As a result, a lot of the motherboard manufacturers are starting to adopt and push the PCIe interface. Similar to SATA, PCIe has also seen evolution, with PCIe 3.0 being the latest iteration of the interface in use. While we stack the two, there are a few more noticeable advantages of PCIe, which include hot-swapping, better performance with storage-intensive work, and advanced error detection and reporting.
Moving to the protocol, PCIe features one of the commonly heard terms in connection to SSDs these days, NVMe (Non-Volatile Memory Express), which aids with better performance. For this, it incorporates parallelism to reduce the latency, and in turn, improve the performance. However, that is not to say the interface does not have any drawbacks, as compared to some of the other offerings, SSDs with PCIe interface (with NVMe) tend to be on the pricier side.
III. Storage Capacity
Once you have decided on the form factor and the interface for an SSD to suit your requirements, the other crucial decision you need to make is to decide on its storage capacity. For, given the cost of SSDs — which is a few times expensive than its HDD counterpart — it is necessary to narrow down your options by bringing your use-case scenario into consideration. Here’s how.
Unless you are very tight on budget and are strictly looking for an SSD to load your operating system along with a few basic, light programs, you should refrain from purchasing a 128GB SSD or a machine with 128GB storage. As, aside from the operating system and a few programs, you can not expect to take backups or store a large number of files on this drive. Plus, the price difference between a 128GB and a 256GB is also not much, and therefore, spending a few more bucks would serve you better in the long run.
A 256GB storage fits in the sweet spot. You can have your operating system and a few essential, high-performance programs loaded on to the drive while also having enough space to use it as a storage system for your different files. Also, as mentioned in the previous point, the price difference is not extreme too, and for what you get out of the drive, it is worth splurging a few extra bucks unless you have budget constraints.
Moving up the ladder, if you wish to store all your files, backups, and games, in addition to the operating system on a drive, a 512GB SSD is your way to go. Simply put, the drive capacity is precisely what you got with HDDs a few years back, which is sufficient for an average user. So if you own a decent collection of files including images, videos, etc, and play a few games, 512GB is an ideal capacity, with prices that are not skyrocketing crazy.
4. 1TB (and above)
For those who can splurge even more and have relatively high-usage,
the 1TB (and above) capacity drives are usually a safe bet. Along with the usual operating system and high-performance demanding programs, these drives allow you to take automatic routine backups (the backup size matters), store images, videos, multiple gaming titles, and pretty much anything you can think of — especially when you go higher than 1TB drives.
IV. Flash Memory Used
As mentioned earlier in the article, SSDs are significantly reliant on the NAND flash memory to work and offer fast performance and longevity. The NAND flash memory is built up of small cells, called memory cells, which store data in the form of bits — 0s and 1s. These bits indicate the current state and are turned ON or OFF through electric charge. And this, in turn, determines how data is stored on the drive. Furthermore, depending on the number of bits stored in a cell, the flash memory can be classified into SLC (Single Level Cell), MLC (Multi-Level Cell), and TLC (Triple Level Cell). Here’s what each of them brings to the table, and what differentiates them.
1. SLC (Single Level Cell)
SLC flash, as the name suggests, can store only a single bit per cell when charged. It is the most basic of the lot, and also the fastest and most expensive. The accuracy levels in terms of the read and write speeds on SLC is unparalleled. Not to mention, longer lifespan and charge cycles, with the ability to operate across a wide temperature range. Since the data loss incurred on these memories is considerably on the lower side when compared to other flash memories, and the lifespan is also impressive, it is the preferred choice for enterprise purposes — since they require accurate data and have less tolerance. Moreover, the higher price tag of the drives (using SLC) is also something that does not put them among the preferred SSD choices for consumer use.
2. MLC (Multi-Level Cell)
As opposed to SLC flash, which stores only one bit per cell, and therefore, has its own share of pros and cons, MLC flash memory, on the other hand, stores two bits in a single cell. As a result, the cost of manufacturing comes down significantly, and so does the drive’s performance and durability. While the performance takes a hit, it is not to an extent where it is considerably noticeable and hampers with regular usage. So, for what it offers, given the reduced cost and the fact that SLC-based SSDs are specifically enterprise-targeted, MLC flash memory SSDs are still preferred choices for servers and heavy workload applications.
3. TLC (Triple Level Cell)
A TLC flash memory can store three bits in each cell, and therefore the name. It is the most common type of flash memory used and compared to the other two, it manages to offer more storage capacity in a smaller footprint and a comparatively lower price point. A trade-off that one has to face in exchange for some noticeable advantages with this memory is that the performance (with the speed, in particular) takes a major blow, and along with it, goes the durability for a toss. However, an advantage that the memory offers is reduced cost, which puts it as a decent option for everyday consumer use.
Similarly, there is also QLC (Quad Level Cell) flash memory, which stores four bits in each cell. However, it is not that prevalent as compared to TLC in consumer-grade SSDs — a large reason for which has to do with downgraded performance and durability.
Now that you have an understanding of the various intricacies of SSD, you can use it to pretty much narrow down your approach and help yourself find the right SSD for your requirements. The right place to start with would be to first determine your use-case, followed by budget. And then, moving forward and deciding the interface type, storage capacity, and form factor, along the way.