Does it Matter Which PCIe x16 slot I Use? [Guide]

Does it Matter Which PCIe x16 slot I Use

With so many slots on your motherboard, it’s easy to become perplexed and unsure which to use.

Does it matter which PCIe x16 slot I use? Yes, it does matter. Some expansion cards are incompatible with all slots and must be placed in a single slot. Because it contains a strong support system, the x16 PCIe is utilised for power-hungry cards.

Does it Matter Which PCIe x16 slot I Use?

  • PCIe
  • PCIe x16 slot
  • Which Cards Should Be Used with the x16 slots?
  • PCIe Slots Compatibility
  • PCIe lanes Explained
  • What is the total number of PCIe slots I have?
  • PCIe Slot Not Working


 PCIe is the abbreviation for Peripheral Components Interconnect Express. It is an interface that allows various components to be connected to the motherboard via slots and expansion cards.

PCIe x16 slot

PCIe x16 slot

 Among all the slots on the motherboard, the PCIe x16 has the highest bandwidth. As a result, it’s particularly useful for cards that draw a lot of power. It appears to be the most difficult to use. Some motherboards contain numerous x16 slots, each one is of a different size.

In contrast to what the name says, PCIe x16 slots feature 8 and sometimes 4 lanes. However, are always true slots with 16 lanes present, and these are the slots to be used for all power-intensive cards.

Which Cards Should Be Used with the x16 slots?

Which Cards Should Be Used with the x16 slots

The x16 slot, as the most powerful, can fit nearly any expansion card, regardless of the requirement. The following are some of the most frequent cards that use the PCIe x16 slot:

  • Graphic cards: This is the most popular add-in card for this slot. The graphic card can only be used in an x16 slot because the lower slots do not fulfill its requirements.

In order to function properly, a graphics card must be linked to a real x16 slot.

Graphics cards are usually utilized to project visuals onto your monitor screens from an external source. Gamers, graphic designers, and cryptocurrency miners are among the most frequent users.

Dedicated graphics cards and integrated graphics cards are the two types of graphics cards. Integrated cards are built-in, whereas dedicated cards must be manually installed on the motherboard via PCIe slots and cards

  • Riser Cards: Riser cards are used to expand the number of available spaces in a game. However, this merely increases the number of ports available; the slot’s overall bandwidth stays unchanged.

They’re also known as splitters because they divide one port into multiple others.

These cards don’t need a lot of power, and they can even be played in an x1 slot. They can work successfully in x16 slots with 8 or 4 lanes because they don’t require a lot of data.

Other cards, such as video cards, sound cards, SATA cards, port expansion cards, and so on, are typically x4 or x8 cards but can be utilized in x16 slots with 8 or 4 lanes.

Related: What Are Motherboard Standoffs

PCIe Slots Compatibility

The PCIe interface can be used both forward and backward. This means that its gadgets can communicate with both earlier and later versions of the software.

In other words, a PCI 3.0 card can be used in a 2.0 slot, but all activities will be based on the lower component’s capacity.

 This type of design slows down performance, and if the inferior component is asked to take too much stress, it may be damaged.

However, if you’re not performing activities that require a lot of data, the difference in performance may be minor. The optimal solution for this setup would be to use slots and cards with the same capacity.

Not only are PCIe devices forward and backward compatible, but they are also cross-compatible. This means that smaller slots can fit inside larger ones. There are four card and slot sizes to choose from x4, x6, x8, and x16). x 1 card can be inserted into any slot. It’s also worth noting that under this configuration, all operations are still constrained by the bandwidth of the lesser component.

PCIe Lanes

PCIe Lanes

PCIe lanes are the primary traffic conduits in a computer. They are data distribution and transmission wires that run from and to the motherboard.

A serial interface connection exists on the PCIe, and it is made up of lanes. Two copper wires connect these lanes. There is constant oscillatory transmission in the configuration, with one pair taking away data and the other bringing data to the motherboard.

Although performance is primarily based on the card’s capacity, 16 lanes are always appropriate for all operations.

PCIe lanes relate to more than just wires. It also encompasses all of the setup’s other components.

Because these lanes act as traffic conductors, it stands to reason that additional lanes will result in a faster flow of traffic. Additional lanes, on the other hand, aren’t necessary unless you’re planning a large setup that will handle a lot of data.

The bandwidth of each lane is determined by the PCIe generation it is using. The bandwidth of one channel is nearly double that of the preceding generation. The bandwidth of each lane is shown in the table below:

Versionx1 (Gb/s)  x4 (Gb/s)  

What Is the Total Number of PCIe slots I Have?

The number of PCIe slots on a motherboard varies depending on the manufacturer. Nonetheless, if you’re unsure how many you have on your motherboard, these are quick and easy ways to find out.

Examine the motherboard: By disassembling the motherboard and manually counting the slots, you can determine how many PCIe slots you have. This may be time-consuming, and you may make mistakes when reassembling the motherboard.

Furthermore, it is not a certain method of obtaining correct results. Consider the next alternative below to avoid this stress.

Visit the following website: Inquiring directly with the makers is a simple way to obtain the correct information. Before this information is displayed to you, you may be prompted to enter some systemic information about your motherboard.

Consult the instruction manual: This information is most likely to be found in the motherboard’s handbook. The handbook that comes with the motherboard always contains essential information.

Luckily, you would not need to read till the end, simply skip to the PCIe section, if there’s any in the table of contents.

Related: How to Connect Power Button to Motherboard

PCIe Slot Not Working

PCIe Slot Not Working

Physical mishandling or internal issues could cause damage to a PCIe slot. The following are possible indications of a damaged slot:

  • GPU cannot be detected: However, the problem is frequently caused by the GPU itself. To validate this, insert another card into the slot; if it still does not function, the problem is with the slot.
  • Slow Performance: When a slot is faulty, the speed of operations is significantly reduced. Its overall performance will be riddled with hiccups at this time.

A PCIe slot may exhibit these symptoms while not being faulty. Here are a few methods for determining whether or not the slot has been fried.

  • Manual Inspection: Examine the motherboard carefully for indicators of possible damage. The slot may occasionally malfunction as a result of excessive dust obstructing it. You could do a good job cleaning up the dust.
  • Make use of a test card: A PCIe test card allows you to run a test on your slot and, if it is bad, it will provide you with a coded breakdown of likely issues.
  • Examine the device manager: The device manager allows you to inspect the health and functionality of any peripherals connected to the motherboard. It is quite useful in determining whether or not a slot is defective.

How to fix

It is not always simple to repair a PCIe slot. It is suggested that troubleshooting be performed by a professional; otherwise, you risk inflicting further harm to your motherboard.

Because the motherboard contains numerous x16 slots, you could use one of them until you either take it to a professional repair shop or buy a new motherboard.

A PCIe slot may not function properly because it has not been enabled or has been disabled. To validate its activation, follow the procedures below.

  1. Start the computer.
  2. When the word “setup” appears on the monitor screen, press the BIOs entry keyword.
  3. Tap enter on the keyboard after selecting the Hardware category.
  4. Navigate through the list until you find the PCIe slot you want to enable.
  5. When you press enter, two options will appear: “enable” or “disable.” Choose “enable.”
  6. Choose the “save changes and exit” option.

This should do. The PC will reboot immediately, and you will be able to test your new configuration.

If the problem persists after this, contact your technician. You’re probably going to be told to purchase a new motherboard, so save yourself the consultation fees and just get a new motherboard.

Related: Can I Use a PCIe 3.0 Card on a 2.0 slot


The PCIe x16 slot sometimes has 8 or 4 lanes. However, there is always a 16-lane on the motherboard’s slot. This 16 lane is referred to as the True slot and should be used for the heavy data feeders. It does matter which x16 slot we use, because the other slots are not configured to meet the requirements of certain cards.

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