PCIe vs. SATA SSDs

Not all SSDs are created equal

The need for higher storage capacities in computers comes with the need for faster data transfer rates. While USB and Thunderbolt cables provide fast speeds, the process starts with the solid-state drive (SSD) for storage. PCIe SSD and SATA SSD differ in a few distinct ways. To get optimal performance from your build, it's important to understand why.

PCIe vs SSD

Important Storage Drive Terms

Before diving into the differences between the two types of drives, you should first understand a few of the terms and acronyms that are used.

  • SSD: Solid-state drive. This is a type of storage medium that doesn't have moving parts. This yields longer lifespans and better performance than traditional spinning hard disk drives.
  • PCIe: Peripheral component interconnect express. PCIe may also be known as PCI Express. This is a slot on the motherboard used to connect everything from graphics cards to solid-state drives. The latest version of PCIe is the PCIe 4.0 specification.
  • SATA: Serial advanced technology attachment. Much like PCIe, SATA is an interface used to connect additional components to the computer. SATA is most often used to connect storage devices and optical drives.

Overall Findings: PCIe SSD vs. SATA SSD

PCIe
  • Smaller size.

  • Can be mounted directly on the motherboard or in an empty bay.

  • More expensive.

  • Faster at 16 GB per second.

SATA
  • Must be installed in a bay.

  • May require an adapter for a secure fit.

  • Higher likelihood to work with older systems.

  • More slots available for expansion.

  • Slower at 6 GB per second.

  • Higher capacity.

While both interfaces can connect an SSD, several differences can influence your choice. Depending on your needs and budget, either could fit the bill for storage. However, for simple variety and availability, a SATA SSD is commonplace and has enough performance to take care of most storage needs.

PCIe SSD Pros and Cons

Advantages
  • Has more flexible installation options.

  • Doesn't require a bay for installation.

  • Faster.

  • Smaller physical size.

Disadvantages
  • More expensive.

PCIe is Smaller Than SATA

If you're pressed for space (for example, when working inside a Mini PC tower), a PCIe SSD might be the better choice. A SATA SSD can fit into a 2.5-inch bay like a normal hard drive, although it might require an adapter to fit securely within the bay. The mounted drive and the necessary cable to connect it also take up space.

PCIe SSDs fit into the motherboard with the PCIe slot. This makes it an ideal choice for builds with limited space. It's also a great choice when you have open slots on the motherboard, but don't have an empty bay to mount a SATA SSD.

PCIe is More Expensive Than SATA

On a per-gigabyte basis, PCIe SSDs tend to be more expensive than SATA SSDs. Those on a budget might prefer the lower-cost SATA SSD option to get the most bang for the buck.

PCIe is Faster Than SATA

The most recent iteration of the SATA interface (3.0) provides a data throughput rate of 6 GB per second. While 6 GB per second is blindingly fast compared to older methods of data transfer, it pales in comparison to PCIe 3.0's 16 GB per second. 

In addition, PCIe also exists in 4.0 and 5.0 formats, with PCIe 6.0 in development. However, few commercially available, consumer-grade motherboards support PCIe 4.0. AMD made the news when they announced their X570 chipset supports PCIe 4.0. As manufacturers introduce more compatibility, the potential speeds for PCIe will increase.

SATA SSD Pros and Cons

What We Like
  • Doesn't take up a slot on the motherboard.

  • Less expensive.

  • Well established format.

  • Systems tend to have more interfaces.

What We Don't Like
  • Requires a bay for installation.

SATA is More Widely Compatible

SATA is a slightly older interface than PCIe, created in 2000 versus 2003. SATA was adopted by companies sooner and therefore has a broader range of compatibility than PCIe. If you're upgrading an older system, the motherboard may not have a PCIe slot available, or one compatible with newer solid-state drives. On the other hand, a SATA cable works with most systems made in the last two decades.

If you're unsure about the kind of connections your computer has, lean toward a SATA SSD. It's almost guaranteed to work with any system functioning today.

SATA Connections are More Numerous

SATA cables connect through a port on the motherboard. PCIe SSDs plug directly into the motherboard. PCIe SSDs demand more real estate than a SATA port does. If you need to connect a large number of drives, SATA is the better option. The majority of motherboards don't have enough PCIe slots for multiple solid-state drives.

SATA Has More Capacity Than PCIe

If you need more storage capacity, SATA SSDs are the preferred option. On average, SATA SSDs have higher storage capacities than PCIe SSDs. A search for the highest-capacity SSDs will reveal a SATA SSD with a storage capacity of 60 TB. While this is a breakthrough device, it's not meant for consumer use with its rather high price point.

PCIe, on the other hand, tends to top out around 2 TB. This is more than enough to contain an operating system and your most-used applications, but can't compete against the relatively low-cost 4 TB and 6 TB SATA SSDs on the market.

Final Verdict: For Most Flexibility Choose SATA

SATA SSDs give consumers more options in an affordable price range. If you don't have an available bay in your case, a PCIe SSD is your best option. For more things to consider, see below.

How to Choose PCIe vs. SATA

While there's a lot of information to digest surrounding both types of solid-state drives, the type to pick boils down to two things: intended usage and case size.

Intended Use

If you intend to build a high-end PC for gaming with all settings maxed and VR use, or if you're building a machine for intensive processes like video and graphics editing, opt for a SATA SSD. These drives have higher storage capacities that are ideal for storing raw files, with the transfer speeds necessary to ensure games load quickly and videos scrub without issues.

On the other hand, if you're building a machine that has no other purpose than surfing the web, checking email, and word processing, a PCIe drive is a great option. The direct-to-motherboard connection takes up less space and gives you fewer cables to manage. While the storage capacity may be lower, you won't need massive amounts of storage for minor tasks—and you can always upgrade to more storage later if you need it.

Case Size

In the computing world, there has been a recent trend of users building micro PCs. These machines are fully functional computers in bite-sized cases—ideal for transporting or for rooms with limited floor space. These cases slot easily onto a shelf or behind a monitor.

However, due to the limited space inside the case, these machines lack the capacity to hold multiple drives. If you have a solid-state drive installed and need more storage, either replace the existing drive (and potentially lose your saved data) or add another drive. While an external drive is a possibility, situations like this are where PCIe SSDs shine.

Because the PCIe attaches directly to the motherboard, you gain additional storage capacity with few hurdles. Just slot the PCIe SSD chip into the appropriate slot, and you're good to go.

Neither type of drive is particularly better than the other. Each has its pros and cons. In the end, PCIe or SATA is largely a matter of preference and of knowing which interface is appropriate at which time.