What Are PCIe x1 Slots Used For?

Are you wondering what the mini-size PCIe x1 slot on the motherboard is for? Well, you have come to the right article because I will tell you all about the PCIe x1 slot in this guide. So, what really is a PCIe x1 slot?

A PCIe x1 slot on the motherboard is used to connect PCIe expansion cards with low throughput (transfer rate). Basically, in simple words, the PCIe x1 slot is used for connecting low bandwidth PCIe expansion cards such as Network Cards, Sound Cards, Port Expansion Cards, and certain PCIe GPU Riser cards. 

It is used for this purpose because it offers the lowest throughput rate (bandwidth transfer speed) out of all the other PCIe slots available on the motherboard.

However, in order to learn why this is the case, we have to dive deeper into what constitutes a PCIe x1 slot and how it functions.

So, without further ado, let’s dive straight into the article.

Peripheral Component Interconnect Express, or PCIe in short, are the slots located on the motherboard that are used for connecting high bandwidth devices to the motherboard, such as GPUs.

PCIe slots are differentiated based on two characteristics, those being;

1. Size
2. PCIe Lanes

On any given motherboard, you will find PCIe slots with varying sizes. Some are as big as the RAM slot, while others are the size of a pinky finger. 

Similarly, like different sizes, these slots also come with a different number of PCIe Lanes. Don’t worry if you cannot comprehend what PCIe lanes are because we will go through them later in detail since they are such an essential concept in PCIe terminology.

The PCIe slot comes in four different sizes

• PCIe x1 slot
• PCIe x4 slot
• PCIe x8 slot
• PCIe x16 slot

The PCIe x16 slot is the largest, followed by the PCIe x8 slot. The PCIe x4 slot sits in the middle of the pack in terms of size, and the PCIe x1 slot is the smallest. 

Due to the PCIe x1 slot being the smallest, it has its own perks and unique characteristics that make it slightly different from the rest of the PCIe slots.

Typically, the smaller the PCIe slot, the smaller number of PCIe Lanes it will have. So, with the PCIe x1 slot being the smallest, let’s see how many Lanes it has.

PCIe lanes are channels or gateways through which the data passes from the expansion card to the motherboard. 

Typically, the number followed by the X in the name of the PCIe slot represents how many PCIe lanes a PCIe slot has. 

Based on this, we can say the PCIe x1 slot has 1 lane, while the PCIe x4 slot has 4 lanes. 

Since the PCIe lanes are the channels for data transmission, it should be no surprise that the more PCIe lanes there are in a PCIe slot, the higher its throughput (data transmission) rate will be. 

Due to technological constraints, a commercial motherboard can have a limited number of PCIe lanes. 

Usually, most mainstream motherboards have anywhere from 20-24 PCIe lanes, which are split between the different PCIe slots of the motherboard.  

They are split in the following way. 

• PCIe x16 slot has 16 PCIe lanes
• PCIe x8 slot has 8 PCIe lanes
• PCIe x4 slot has 4 PCIe lanes
• PCIe x1 slot has 1 PCIe lane

Now, it is up to the motherboard manufacturers to decide how they want to split up the total 20-24 PCIe lanes of the motherboard in relation to the information mentioned above. 

Every motherboard has one PCIe X16 slot because modern graphic cards require 16 lanes to work optimally. So, that leaves only 4-8 remaining PCIe lanes, which are then split based on the motherboard’s needs.

If you want to find out more about PCIe lanes and how they work, refer to my in-depth article on how to check how many PCIe lanes I have.

Like every computer hardware, motherboards also undergo major technological advancement. Each advancement comes with a new version of the PCIe slot, and increased throughput speeds follow suit. 

With each new generation of PCIe slot, the lane transfer speed doubles as opposed to the previous generation. 

As you have seen from the chart above, the speed of the PCIe x1 slot has constantly been changing; therefore, not all PCIe x1 slots are the same. 

Currently, we are the 5th generation PCIe technology, with 6th just around the corner. However, most commonly, you will come across either the PCIe 3.0 or the PCIe 4.0 x1 slots. 

This is primarily because the PCIe slots with more lanes get the upgrade to the next version. Since the PCIe x1 slot has the least number of PCIe lanes, its upgrade happens at the end.  

The PCIe 3.0 or PCIe 4.0 versions aren’t outdated yet because they still provide good enough throughput speeds of 1GB/s and 2GB/s, respectively, which is enough for most PCIe devices.

I am trying to make the point that despite being stuck on the older PCIe version, you won’t get any impact in performance or compatibility with the PCIe x1 slot.

Don’t let the small size of the PCIe x1 slot fool you. This PCIe slot has many uses and is much needed on a motherboard because it only takes one Lane out of the total lanes of the motherboard. 

Many expansion cards don’t need a lot of bandwidth to work; for these expansion cards, the PCIe x1 slots are an ideal fit. The following are the expansion cards that use the PCIe x1 slot. 

1. Sound Card
2. Network Card
3. Video Capture Card
4. USB Expansion Card
5. SATA Expansion Card
6. Riser Card
7. TV Tuner Card
8. Low-end GPU

1. Sound Card

A sound card is an expansion card that encodes sound coming from the headset to the computer. It replaces the built-in audio chipset of the motherboard. The sound card is highly sought after by audio enthusiasts and purists because of its superior sound handling capabilities.

A sound card produces much cleaner and more accurate audio than the motherboard’s onboard audio chipset. 

The PCB of the sound card is enclosed in a separate isolated chamber. Therefore, it is not prone to interference like the onboard audio DAC of the motherboard.

To perform its task, a sound card does not require a lot of data, so the low bandwidth PCIe x1 slot is ideal. 

2. Network Card

A network card is an expansion card that brings internet connectivity to the motherboard. That connectivity can be both in the form of wireless or wired.

These are two types of network cards, those being

• PCIe Wi-Fi cards
• 1GB/s PCI Express Ethernet Network Cards

The PCIe Wi-Fi card is pretty self-explanatory. Not every motherboard comes with built-in Wi-Fi, and the USB Wi-Fi adapters that many of us buy are quite crappy. 

Therefore, many people prefer using PCIe Wi-Fi cards. These cards plug into the PCIe x1 slot and effectively turn your motherboard into one having built-in Wi-Fi. 

These Wi-Fi network cards work on the PCIe x1 slot because they don’t generate a lot of data, which results in them requiring less throughput (bandwidth transfer) rate. 

The Ethernet network card is primarily used for server machines. The Ethernet card brings a lot of high-speed ethernet ports to the motherboard. 

Most people buy these Ethernet network cards because they want a faster ethernet connection. Therefore these ethernet cards come with ports supporting up to 1 GB/s speed. 

There are Ethernet network cards with more speeds as well, but that requires a PCIe slot with better throughput, so up to 1GB/s ethernet cards, you can use on a PCIe x1 slot. 

3. Video Capture Card

A video capture card is primarily required by gamers, streamers, and content creators. A video capture card takes the video signals and converts them into a form that can be stored on the computer. 

Video capture cards can record a live video or broadcast signal without any boundaries. You can take advantage of the video capture card in multiple situations. They can be connected to sources like TV, gaming consoles, gaming PCs, and even cameras.

A video capture card built to output video data at 1080p resolution can work optimally on a PCIe x1 slot. However, a more powerful 4k support capture card will require a PCIe slot with a high lane count. 

4. USB Expansion Card

The USB card is an expansion card that increases the number of USB ports on your motherboard. In some motherboards, there are only a handful of USB ports, making it a hassle to connect multiple USB peripherals.

In that case, users opt for the USB expansion card, which plugs directly into the PCIe x1 slot of the motherboard and works flawlessly. 

5. SATA Expansion Card

The SATA expansion cards act similarly to the USB port expansion cards. These expansion cards increase the number of SATA ports on the motherboard. 

A sufficient quantity of SATA ports is required because these ports are the primary connection for the HDD and the 2.5” SSD of the PC. 

There are not enough SATA ports in some motherboards, especially the older ones. Therefore, the SATA expansion card is required, and it works like a charm on the PCIe x1 slot. 

6. Riser Card

The riser card splits the PCIe slots into new ones. Hence, increasing the number of PCIe slots.

With the PCIe riser, you are only increasing the number of PCIe slots. The number of PCIe Lanes stays unaffected.

When the PCIe slots are split, the bandwidth splits equally. If the main PCIe slot on which you are installing the PCIe riser card has 2GB/s throughput (bandwidth) rate, then split ports will have a combined throughput (bandwidth) rate of 2GB/s.

For example, suppose the main PCIe slot bearing 2GB/s bandwidth is split into 4 additional PCIe slots. In that case, the 4 additional PCIe slots will have a combined bandwidth of 2GB/s.

7. TV Tuner Card

A TV tuner card embeds basic TV connectivity into the computer. For example, using the TV tuner card, you can connect a coaxial cable to the computer, enabling the computer to display TV channels.

Some TV tuner cards also have the functionality of recording a live TV channel for offline viewing.

These expansion cards are great if you don’t have an extra screen in your room and want to use your computer’s screen for watching the TV or recording it.

8. Low-End GPU

While GPUs are not necessarily used on the PCIe x1 slot, you can sometimes get away with using a low-end GPU on a PCIe x1 slot. 

I am talking about GPUs like the GT 710, GT 1030, etc. Any GPU with 1GB VRAM can be used on the PCIe x1 without sacrificing performance. 

This can be handy when you want to use the main PCIe x16 slot of the motherboard for any other important expansion card and want to rely on the PCIe x1 slot for your GPU.

It can come in very handy if you want to use the PCIe x16 slot of the motherboard for any other important expansion card and want to rely on the PCIe x1 slot for your GPU.

Related Guides

Check out some of our related motherboard buying guides.

• Best Motherboard for Ryzen 5 3600
• Best Motherboard for Ryzen 5 5600X
• Best Motherboard for Ryzen 7 5800X
• Best Motherboard for Ryzen 9 5900X
• Best Motherboard for Gaming
• Best B550 Motherboard

Check out some of the other related motherboard guides.

• How to Tell if Motherboard Is Dead or Bad
• Does It Matter Which PCIe x16 Slot I Use?
• When to Upgrade Motherboard?
• PCIe 3.0 vs 2.0
• How to Test Motherboard Without CPU?

I hope you have now understood what the PCIe x1 slot is used for. Although seemingly small, there are a lot of expansion cards that can be installed on the PCIe x1 slot. 

To quickly recap, the PCIe x1 slot is primarily used for network cards, sound cards, video capture cards, USB expansion cards, SATA expansion cards, Riser Cards, TV Tuner Cards, and Low-end GPUs. 

The PCIe x1 slot is an ideal fit for these expansion cards because they don’t require a high amount of bandwidth. Therefore, since the PCIe x1 slot has a low throughput rate, it suits these expansion cards.

 Now, it is time to wrap up this article. Before you sign off, do tell me in the comment section how many PCIe x1 slots your motherboard has. Also, I am interested to know what you use them for.