Which PCIe Slot is Best for Your Graphics Card? – Find Out All About It

There are a ton of things that you would want to keep in mind when designing a gaming PC. Gaming PC machines are in great demand in the market as of now. Today, you can find thousands of PC designers developing innovative gaming products that sometimes outdo the ones that are manufactured by reputed brands.

They are so good. The most critical component of a gaming PC machine is the graphics card. The graphics card does a lot of work in the PC machine, including giving you stunning visuals. This is an essential part of a gaming PC device.

It is because of this reason, you would want to know the PCIe slot that is best for your GPU. The PCIe slot that you should use for your graphics card would be the PCIe x16 slot. You can find it near the CPU.

It comes as the recommended slot for your GPU. The PCIe x16 slot comes with 16 PCIe lanes that provide you with immense performance compared to the rest of the PCIe slots on the PC. This is because, on most motherboards, the first PCIe slot is the x16 slot.

Importance of the PCIe slot for the graphics card

When you have a dual or triple graphics card, you may need to do a couple more of things based on the motherboard that you are using there. Besides, the maker of the GPU also makes a difference; it could be the AMD or Nvidia graphics cards.

Most of the PCIe lanes come with a limited performance on any top-end motherboard & CPU. So, a PC device with a dual or triple AMD or Nvidia GPU can’t be allocated with 16 lanes. That is why we have compiled this post on the right PCIe slots for your graphics card.

Once you have completed the post, your doubts will be cleared. We will be taking a look at different things, like why the slots matter and what kind of graphics cards you might want to use, and have provided you with the FAQs as well.

Which PCIe Slot is Best for Your Graphics Card

A small introduction on PCIe slots and lanes

If you already know how the motherboard appears, then it is okay. But for our readers who have never seen a motherboard, we would like to give them a small introduction so that it will help them process the post better.

Now, the motherboard has several PCIe slots on it. These PCIe slots come in many different configurations that can find out how many lanes they have. The x1 slot comes with a single lane on it, and the x4 and x8 slots have 4 and 8 lanes, respectively.

That brings us to the largest PCIe slot found on the motherboard, which is the x16 slot. It comes with 16 PCIe lanes. What do the lanes represent? The lanes represent to you the capacity of the bandwidth that you get pairing the device.

It is evident that the x16 offers you with the highest bandwidth. This is most ideal for a graphics card that can provide you with a high amount of data like the graphics card. You will want to know that the GPU can offer you with plenty of information that needs to be transferred.

But, of course, not all of the x16 slots are designed and made with the same capacity. Some of them do have a large size that you want, but most provide you with 4 or 8 lanes at the most. So, you will need to select the x16 slot for your graphics card wisely.

On the processor, you would want to note that the blue x16 slots are the longest ones. They are present on most of the top-end models in the market. Obviously, they come with a graphics card, and the smaller X1 cards are used for low-end models, like network cards.

Which PCIe Slot is Best for Your Graphics Card

Which PCIe slot for GPU is good?

You know by now that the most preferred slot for using the graphics card is indeed the x16 slot. But you may want to select the right x16 slot when you have several of them on the PC device. This happens sometimes.

PC designers & developers might understand this aspect of things. Perhaps, they would have used it earlier in their production line. If you look at any motherboard, you can notice that it comes with 2 PCIe x16 slots in them.

But only the top slot is the actual x16 slot that comes having 16 lanes in them. The others that are located elsewhere have only 4 lanes. That is concerning because you need to place the GPU accurately in there to extract the right kind of performance from them.

Which PCIe Slot is Best for Your Graphics Card

What about the x8 slot?

So, when you have several graphics cards or when you notice that the main x16 slot is not there, then what do you do? The answer to that would be to make use of the next best option in there, which is the x8 slot.

That is right. The x8 slot comes in the same size as that of the x16 slot but has only 8 lanes on it. Not surprisingly, many users tend to confuse it with the x16 slot and fix it wrongly. But you get lesser performance from it, which is effectively decreased if you use the x8 slot and not the intended x16 slot.

Please do note that the x8 slot is not found on low-end models. However, you can find the x8 slot on most mid-range and top-end models. So, why can’t a PC machine come with more than one single x16 slot?

It comes down to the nature of the PCIe lanes where you can find the PC device. Primarily, there should be more than 20 PCIe lanes that are accessible at any given time. So, when you actually have 2 full x16 slots, it brings to you 32 PCIe lanes.

You can’t find this kind of setup on a top-end motherboard, and the bandwidth is immensely decreased on the several graphics cards. You would want to remain on the lane that is suitable for your PC device.

For example, you have the MSI MGP Z490 motherboard, which has 3 PCIe x16 slots on it. They have a similar size, but the lane count is much different from each other. On the top, you have close to 16 lanes; in the middle, you have 8 lanes; and at the bottom slot, you have 4 lanes.

If you want to use this for your GPU, then you will need to use the first x16 slot. This can provide you with a complete performance. When you want to make use of 2 GPUs, then you have to make use of the first and the second PCIe x16 slots.

When you do that, the performance of the first PCIe x16 slot is incredibly reduced. This is something that you definitely don’t want to happen. You can make use of the final x4 slot along with the third GPU if you want to for 4 lanes found on the NVMe SSD Card.

Which PCIe Slot is Best for Your Graphics Card

A little about Nvidia SLI and AMD Crossfire

Those of you who swear on gaming would have definitely heard about these two terms. Nvidia & AMD are two famous brands that have produced stunning products for the market. Luckily for you, they offer you with the multi-graphics cards opportunity.

Though the task is done quite differently, they get it done. You need to make use of two graphics cards that can work together to boost your GPU performance on PC devices. Please do note that the Nvidia SLI requires an x8 slot & the AMD Crossfire operates on an x8 slot and an x4 slot.

Does plugging the card in an x8 slot affect the performance of the GPU?

It does a bit. When you plug the card into the x8, your GPU performance becomes slightly affected. You already know that by now. But according to most gamers, the difference in the performance is slight when you use it on the x16 slot.

We are not sure about those details and hence may not want to make tall claims here; however, if you have done it or tried it before, we would love to hear on thoughts on that. While some tests have shown a difference of only 2%, some have delivered more than 8%.

This probably has to do with the components infused in your PC machine. If you are using a top-end model laptop or PC, then you might experience a slight drop. But when you are using a 2-year-old gaming laptop or PC device, then you may experience it further down.

But for casual gamers, the x8 slot with your GPU would suit just alright. You might want to consider using it. The drop in performance should not be a factor for you not wanting to use two or more GPUs. You can do it with little or no difference in performance for mild gaming.

Which PCIe Slot is Best for Your Graphics Card

How to know which PCIe slots you have?

This is something that any user should be able to know. Otherwise, how will you know what kind of GPU to use on the PCIe slot? The best method to know the kind of PCIe slot would be to check the slot labels.

You can find them labeled on the motherboard; the PCIe slots can be easily found for you to know how to place your graphics card. A few low-key graphics cards come with a shallow bandwidth requirement, and you can make use of the smaller connections.

There is a low PCIe lane requirement. For example, when you need to the graphics card, you have the ASUS NVIDIA GeForce GT 710 that requires the x1 slot. In this GPU, you would want to make use of the x1 slot.

You can, of course, work on the large slots by installing on the x16 slot or even on an x8. There is also the x4 slot that may not provide you with the same functionality. Why a low-lane requirement?

The reason for having a low-lane requirement on the PCIe slot is that you do not want to generate the data. You can use a low-end GPU to add display support for your PC when the motherboard does not come with video output ports.

This offers you a quick performance from getting a professional gaming GPU. You would want to need more than 1 PCIe lane for your graphics card.

Which PCIe Slot is Best for Your Graphics Card


Does it matter which PCIe slot you use?

Yes, it does matter which PCIe slot you want to use on most of the motherboards. That is because the second PCIe slot only provides you with 4 or 8 PCIe lanes depending on the make. So, you will want to know what has to go in the appropriate PCIe slot you are planning to use.

Which PCIe slot is the fastest?

The PCIe slot that is the fastest is PCIe 3.0. Though the PCIe 4.0 came with the 16 GT/s data rate when you compared it to the earlier 8 GT/s. You will be delighted that all of the PCIe 4.0 lane configurations support double the bandwidth of PCIe 3.0

It maxes out at 32GB/s in a 16-lane slot. You also have them coming in at 64GB/s on the bidirectional travel that has been considered. So, there you have your answer on which PCIe slot is the quickest.

What is the PCIe x16 slot used for?

The primary function of the PCIe x16 slot is to let your motherboard to connect with the important components. That is because they can offer you with the key functionalities. The slot can provide you with several customization capabilities and upgrade options.

This provides you with the ability to go beyond preloaded features like storage and graphics. You can make use of them and take things further in the developmental aspect of things for getting better visuals.

Does PCIe 4.0 make a difference?

Of course, the PCIe 4.0 makes a massive difference on your motherboard. However, you will want to know that the main benefit of having one in the first place is that it allows you to upgrade to new SSDs and GPUs.

This happens in the development of the hardware. The PCIe 4.9 SSDs help you to provide with the maximum read & write speeds than the PCIe 3.0 SSDs. But some of the main real-world advantages would be the areas like loading times and transferring a large file.

Are all PCI slots the same?

Not necessarily. Each PCI slot has a different function and duty if you can say that. There are, at the moment, 3 primary PCI motherboard connectors that are known as slots. Each of the PCI slots appears kind of different from the others and accepts different devices.

You may not want to place a PCI card in the wrong slot because it has the potential to damage the card. Besides, it can damage the entire PC device, and that is something that you do not want to happen.

Final thoughts on which PCIe slot is best for your graphics card

We have come to the end of our post on which PCIe slot is best for your graphics card. We hope that you benefited from the above post. You know what to do now. You also see the difference between a real PCIe x16 slot & an 8x slot.

It can affect their performance incredibly. You also read about what is required to use SLI or Crossfire. Besides, you also found out how many PCIe lanes they need. The PCIe interface can be cross-compatible, which is a good thing.

Now, you can make use of your graphics card on the various types of slots. But, when you want to use a high-end graphics card, please go in for the x16 slot. Remember to choose the PCIe slot for GPU only after looking at the lane count of the PCIe slot and the GPU connector.

When using a low-end graphics card, you will need only 4 lanes to run efficiently on x4 slots. If you found this post helpful, then share it with your friends & colleagues. If you have some queries or doubts, then please feel free to let us know about it; we would be delighted to help you clarify your questions through the comments section.

James Smith has always been intrigued by electronic products since his childhood. After his post graduation in electronics from a popular university, he decided to pursue a career in the electronics sector. But his calling for writing about these marvellous pieces of work got the better of him. That is how UBG was started. With a writing career spanning more than 12 years, James has worked on several hundred product reviews. During his free time, he like to spend time with his pet dog and relax in the swimming pool.