SATA Vs PCIe – What are the Differences?

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Trying to choose between SATA and PCIe SSDs but can not choose the appropriate one for yourself? Then through this article, we might just be able to help you to choose the one you need.


What Are PCIe and SATA SSDs?

Before understanding the differences between these two types of drives, you should first know a few of the terms and acronyms that are used.

SSD: These are solid-state drives. It is a type of storage medium that does not have moving parts. It lasts longer and performs better than the traditional hard disk drives.

PCIe: Peripheral component interconnects express. PCIe is also known as PCI Express. This is a slot on the motherboard of a PC that is used to connect everything from graphics cards to solid-state drives.

SATA: Serial advanced technology attachment. It is pretty much similar to PCIe when it comes to its basic uses it. SATA is also an interface used to connect additional components to the computer. SATA is mostly used to connect optical drives and storage devices.

Now we can talk about the qualities to compare these two SSDs.

Transfer Speed

PCIe 3.0 has an effective transfer speed of 985MB/s per lane. Since PCIe devices can support 1x, 4x, 8x, or 16x lanes, we’re looking at potential transfer speeds up to 15.76GB/s. SATA SSDs can not reach that level! But what does it mean? Would a PCIe SSD with 16x lanes be 25-times faster than a SATA SSD? 

Theoretically, that might be possible, but it is hard to find a consumer-grade SSD with that number of data lanes. Normally you’ll be deciding between 2x and 4x lanes, which means you will most probably get a maximum transfer speed closer to 3.94GB/s. And even after that, the only noticeable difference between PCIe and SATA will be visible when transferring big files that take a while. For example, If you’re playing a video game, and you want faster load speeds when starting up the game or changing maps only, both PCIe SSDs and SATA SSDs will feel fast.


Every drive has its performance numbers, but did you know that the SATA and PCIe formats have their performance ceilings too? SATA III drives are almost exclusively limited to a maximum sustained read and/or write speed of 6Gbps or roughly 550MBps. Although a SATA hard drive is never going to hit such speeds, SATA III SSDs will have no problem meeting this threshold in synthetic testing.

PCI-Express drives are faster, but still, they are limited by the speed of the memory chips on the drive itself and the generation of PCI-Express that they are designed for. PCIe 3.0 drives have a usual maximum speed of 3,500MBps, while PCIe 4.0 drives have a typical maximum speed of 5,000MBps.

Other performance metrics that are important to note include random read and write speeds. These are less stark between SATA and PCIe drives. While PCIe drives can have random read/write speeds (3-5 times greater than their SATA counterparts) in reality, that achieves between a two and three times improvement, and only in longer transfers. In short transfers, the performance gap is much thinner than that. You would feel the effective difference between these drives types depending mainly on what you use your system for.

Hardware Compatibility

SATA SSDs have better hardware compatibility than PCIe SSDs. If you get a SATA SSD, Whatever desktop or laptop computer you are using right now, it is pretty much guaranteed to work with that.

The Connection

The SATA cables that are used to connect mechanical hard drives are the same ones used for the SATA-based SSDs. SATA III, which is the most recent iteration of the interface, has a maximum throughput of 6 Gbps roughly 600 MB/s in real-time performance. Due to their popularity, the SSDs based on the SATA III interface are the lowest priced SSDs available. These are usually 2.5 inches.

The PCI Express interface has a high-speed serial expansion card format.PCIe interfaceuses point to point interface. This interface is mainly used to connect Graphics cards. PCI Express-based SSDs are plugged into an expansion slot on the motherboard. It provides both data and power connections.

PCI Express can allow more bandwidth through faster signaling and multiple lanes.  SSDs based on PCI Express have a direct connection to peripherals and it makes them perform much better than SATA which uses cables to connect to the motherboard resulting in high latency.


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

PCIe SSDs fit into the motherboard with the help of a PCIe slot. This makes PCIean an ideal choice for builds with very limited space. It’s also a great choice when you have open slots on the motherboard, but not an empty bay to mount a SATA SSD.


Although the prices of SATA III-based SSDs have come down by a considerable margin nowadays, the fastest SATA-based SSD you can buy, Samsung 850 Pro costs approximately $1000 for the 2TB variant while the newer and NVMe SSDs cost hundreds of dollars depending on the storage space needed.

With their smaller size and greater performance ceiling, PCIe drives are more expensive than their SATA counterparts.


We have shown the properties of the SATA and PCIe SSDs to you. If you’re on a budget, you can go with SATA. If you want maximum performance that includes big file transfers, PCIe might just be a good choice for you. Both are most convenient to use in the M.2 form factor, and both are demonstrably better than HDD in terms of speed. So it seems like you really can’t go wrong with any of them.x

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