What PCIe Slot do I Have?

It has been a while since the introduction of the PCIe standard and all we can say is that over the years we have seen nothing but tremendous improvements.

Because the standard was introduced in 2004, new motherboards from that era have been coming with the PCIe slot as a replacement for the previous AGP and PCI ports that were much less efficient in comparison.

If you have a PCIe slot on your motherboard, you can add any PCIe peripheral to the board to get some extra features. We’ll talk more about the customization options a little later, but know you’re probably wondering, what PCIe slot do I have?

Answering this question will require a little bit of digging. Since PCIe slots exist in multiple configurations, finding out which one you have will require some research into the motherboard itself.

What PCIe Configurations Can You Find?

When most people ask, what PCIe slot do I have, they are referring to the configurations of the slots on their motherboards.

The PCIe standard lays out PCIe slots in 4 main configurations that are easily available for consumer-grade computers.

There’s a fifth rare configuration that is mentioned in the standard, the PCIe X32. However, the four main ones which we’ll look more into are the X1, X4, X8, and X16.

A combination of these four main slots is used on motherboards to grant users the ability to install things like network cards, graphics cards, sound cards, and I/O expansion cards among other things.

If these slots are used well, you can get above-decent performance from your computer with very little effort on your part. To do this, you’ll need to know the slot you have.

Let’s first see some of the characteristics of the slots that will help in determining the slot configurations on the system.

PCIe Sizes
PCIe Slots come commonly in x1, x4, x8, and x16 sizes. The slots also have 1, 4, 8, and 16 lanes respectively. Source savel.org

Also Read: 5 Best MSI Motherboards for Gaming in 2021

The X1 Slot

This is the smallest slot on the PCIe standard. It may not appear small in physical size because manufacturers can use a larger physical slot but with fewer pins.

Nevertheless, in terms of lane count, this slot has just one lane. As a result, this slot gives you the least bandwidth you can get on any PCIe slot in a certain generation. We’ll see more on PCIe generations later.

The standard PCIe X1 slot measures 25mm in length. It doesn’t occupy a large space on the motherboard and this makes sense because it only has 18 pins that are used to interface with the peripheral device.

The slot is used for PCIe devices that do not have large bandwidth requirements. This lets users add devices like some Wi-Fi cards that can be supported by the motherboards.

The X4 Slot

A standard PCIe X4 slot is slightly bigger than the previously mentioned X1 slot. And just as it is larger, it has more lanes.

With four lanes, the X4 slot is a better candidate for cards that require a little more bandwidth than the X1 slot can offer.

It’s also worth noting that if you have an X4 slot, you can fit an X1 card in it and it will work just fine. Granted, the setup will work at the speed of the X1 card even though it’s using an X4 slot.

With the 4 lanes, users get a total of 32 pins on a slot that is, according to the PCIe standard, 39 mm long.

The X8 Slot

With an X8 slot, users start to transition into the high-bandwidth territory where the cards need to push a lot of data into and out of their systems.

Many motherboard manufacturers use an X16 slot on the motherboard with the corresponding pins and lanes for an X8 slot so differentiating them will require more than just a quick look.

Nevertheless, the standard X8 slot falls somewhere between the X4 and the X16slot in length which is 56 mm.

The entirety of its length houses the 49 pins that are required to interface with whichever PCIe card can fit in the slot.

The X16 Slot

In terms of lane counts alone, this is the largest PCIe slot you can get on a mainstream motherboard. It has 16 lanes and it, therefore, comes as no surprise that the slot is meant for devices that require a lot of bandwidth like a graphics card.

The length of the card is about 89 mm and it exposes about 82 pins that are used to interface with the PCIe cards.

Many motherboards have a single PCIe X16 slot that is mostly reserved for a graphics card. Then a mix of the remaining slots is provided for any additional components.

Also Read: Best Motherboards for SLI

What PCIe Slot do I Have?
Different PCIe slots are used together on the same motherboard for a variety of peripheral components. Source: deskdecode.com

What PCIe Slot do I Have?

With the above information, it’s easy to start getting into identifying the PCIe slots on your motherboard. One thing you will always need to note is that you will always need to countercheck the slot with the data on the motherboard’s manual to make a correct assessment.

Here are some of the ways you can determine which PCIe slot you have.

Also Read: Why is a Motherboard Important?

1. Consulting the Manual

This is possibly the source of the most accurate information about the board that you can get. The motherboard’s manual will come with the device itself on purchase and it will give you a detailed breakdown of all the slots you have.

If you don’t get the hard-copy manual, then a web manual will also do. By visiting the manufacturer’s website, you can also get accurate product descriptions.

2. The Board

Sometimes the board’s slots are labeled. If this is the case, check the labels on the board next to the PCIe slots. You may get all the information you need here.

3. Consult an Expert

An expert can help you get information about your motherboard, including the PCIe slot that you have. Find a reputable individual or company and see if they can help determine which PCIe slots you have. You may need to pays for some of these services so ensure you are well aware of the process first.

4. Use a Software

You can use a program to get accurate information on your motherboard easily. Software such as Belarc Advisor can scour your PC for information and give you the details in a few easy steps.

PCIe X1 and X16
Some high-end motherboards have several PCIe X16 slots, allowing the use of multiple graphics cards. Source: digitalcitizen.life

PCIe Generations

We’re saving this for last because with PCIe devices being backward-compatible, the generation of the slot doesn’t determine whether or not a particular peripheral will work.

It does, however, determine the operating speed of the device. Nevertheless, using all or a combination of the methods above can leave you with accurate results about which PCIe generation(s) you have.

Also Read: Which PCIe Slot for Wireless Card?


We have seen that to determine what PCIe slot do I have, we need to make use of a combination of tactics to come up with the information.

A good point to start from is knowing the characteristics of the different PCIe slots as this can help determine which slot we have.

To accurately determine which slot you have, you’ll need to consult a trusted knowledge-base like a user manual or reputable individuals.

However, to get this information quickly, then you can install a piece of third-party software and with a few clicks, get all the information you need.

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