Difference between PCIE and SATA

Solid state drives have improved a lot in recent years. What used to be expensive for most of us five years ago is now much cheaper. However, there is currently a lot of confusion surrounding the different types of SSDs and available interfaces. Almost any SSD provides a noticeable performance difference over a mechanical hard drive. SATA, NVMe and M.2 based SSDs are the most popular available right now and people are not sure which one is right for them or which one works best. Here we will explain what the difference is between PCIe and SATA.  Difference between PCIE and SATA

SATA (Serial ATA) and PCIe (Peripheral Component Interconnect Express) are the interfaces that are widely used by SSDs (Solid State Drives) that are available on the market today. There are many key differences between these two interfaces that can create a lot of confusion among consumers. So, let’s take a look at these differences:

CONNECTION  Difference between PCIE and SATA

Serial ATA (SATA) is the most widely used interface for connecting SSDs today. This interface has been around for quite some time. Do you know the SATA cables we use to connect our mechanical hard drives? That is exactly the cable that is used for SATA-based SSDs as well. SATA III, the most recent update for this interface, has a maximum throughput of 6 Gbps which is roughly equivalent to 600 MB / s in real-time throughput. Due to their popularity and the number of manufacturers making SATA-based drives, SSDs based on the SATA III interface are the lowest priced SSDs available on the market today. These SSDs are typically 2.5 inches and can be found online for as little as $ 50.

The PCI Express interface is a high-speed serial expansion card format that uses a point-to-point architecture. This is the same interface that we all use to connect our graphics cards. PCIe-based SSDs plug into an expansion slot on your motherboard, which provides both data and power connections. So what is its role in SSDs? Unlike SATA-based SSDs, PCIe can allow more bandwidth. Due to direct connection to peripherals, PCIe-based SSDs perform much better than SATA counterparts that use cables to connect to the motherboard, which in turn results in high latency. For example, the Samsung 960 Pro NVMe SSD boasts about 4-5 times the performance of the SATA-based Samsung 850 Pro.


The performance gap between SATA and PCIe is quite large, as SATA III maxes out at 6Gbps or 600MB / s. On the other hand, two lanes of PCI Express 3.0 can provide more than 3 times the performance of a SATA III-based SSD at nearly 2000MB / s. All this while consuming just 4% more power than a SATA III SSD. This is clearly a win for the PCIe interface.

Even the cheapest PCIe-based SSDs will offer a significant performance gain over SATA-based SSDs and if you go for the higher-end ones, the performance will be much better. To this day, the SATA III interface is considered a bottleneck for SSDs because it is capped at approximately 550MB / s in real-world benchmarks. If your demands are quite high and you want a higher performance SSD, you probably already know which interface you should go for.


SATA III SSDs are generally available in 2.5 inches, which use SATA cables to connect to the motherboard. As a result of indirect cable connection, this can result in high latency that can affect the maximum potential of the SSD.

M.2 is a new slot on the motherboard to allow the installation of smaller SSDs in compact devices such as laptops. Today, this slot has made its way to various ATX, Micro-ATX, and Mini-ITX motherboards that are also used in desktop computers. There is a lot of confusion surrounding M.2 SSDs among consumers. Make no mistake, the M.2 slots on the motherboard can have both SATA and PCIe lanes going into the slot. This totally depends on the motherboard you have. You’ll have to dig into the specs to make sure of that.

Samsung 850 EVO SSD, for example, can be purchased in 2.5-inch or M.2 format. Regardless of the form factor you choose, both SSDs max out at SATA III speeds of 600MB / s.


Non-Volatile Memory Express (NVMe) is a rapidly developing communication protocol that enables an SSD to make effective use of a high-speed PCIe bus in a computer. PCIe is the same interface used by graphics cards, sound cards, and Thunderbolt. PCIe 3.0 offers almost 1GB / s per lane. If you put a card in a four-lane slot, you’ll basically get 4 times the bandwidth, at almost 4 GB / s. Now this is insanely fast, even when compared to SATA-based SSDs. In fact, NVMe is considered a replacement for the AHCI protocol, used by most SATA-based SSDs today.

Now, on the other hand, the M.2 slots that we discussed earlier, may have PCIe lanes going into the slot. Therefore, PCIe-based M.2 SSDs use the NVMe protocol for blazing speeds, easily managing speeds in excess of 2000MB / s. Currently, the fastest consumer SSD in the world is the Samsung 960 Pro NVMe M.2 SSD, which can provide sequential read speeds of nearly 3500MB / s. This is a breakthrough over the 550MB / s offered by high-end SATA III SSDs. The NVMe protocol will only get better in the future, so if you want the absolute best speeds, PCIe-based SSDs are the ones to consider.

Aside from this, Intel has been hard at work on a newer and much faster SSD called Intel Optane Memory, based on its own 3D Xpoint technology. Although Optane is based on PCI Express, Intel claims that Optane is 4.42 times faster than a NAND-based NVMe SSD in terms of I / O operations per second. They also promise 6.44 times lower latency on Optane. Although you cannot buy it right now, it is in development and is expected to be available by the end of next year. So from this we can be sure of the fact that PCIe-based SSDs are the future.

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