Does PCIe 4.0 Work with 5.0? [Answered, Differences]

PCIe slots are evolving faster. As the hardware we use in our PCs is becoming more powerful, the slots used to connect them to the motherboard must also become competent. We can see that CPU, GPU, RAM, SSDs, etc. are becoming more efficient and effective. So, it is important to have a high-performing slot to use them efficiently.

Introduced in the year 2003, PCIe has become a standard for connecting many vital hardware components to the motherboard and aids in communication with the CPU. Since 2003, there are six generations introduced with the PCIe. But you can commonly find PCIe 4.0 and PCIe 5.0 in usage.

In this article, we are going to discuss the differences between the 4.0 and 4.0 versions of the PCIe and whether a 4.0 can work with a 5.0 PCIe slot.

Does PCIe 4.0 Work with 5.0

Does PCIe 4.0 Work with 5.0?

Yes, You can use a PCIe 4.0 with a 5.0 because these slots are forward and backward-compatible. Despite the generation, you can connect an older gen device to the latest gen slot or you can use the latest gen device to an older gen slot. Your device will work perfectly alright but the performance will be limited to the slot and device generations.

For instance, if you are connecting a PCIe 4.0 GPU to a 5.0 slot, the GPU will run only with the specifications of 4.0. Similarly, if you are using a 5.0 GPU in a 4.0 slot, the GPU will run like a PCIe 4.0 device. In order to get the full benefit of PCIe 5.0 or 4.0, you need to connect the same generation device to the same generation slot. Therefore, the PCIe technology is compatible in both ways, the performance is limited to the lowest generation.

Let us now discuss the differences between PCIe 4.0 and 5.0 which are currently in use with many tech products.

PCIe 4.0 vs PCIe 5.0

The performance of 5.0 is double that of 4.0. The major specifications to be considered are the Speed per lane and the Maximum bandwidth. Here is a table that shows the differences between the two PCIe generations.

PCIe 4.0 PCIe 5.0
Year 2017 2019
Speed 16GT/s per lane 32GT/s per lane
Bandwidth (Maximum) 64GB/s 128GB/s

As we can see, the speed of 5.0 is twice as of PCIe 4.0. Similarly, the maximum bandwidth is also twice the performance of previous generations. Therefore, upgrading your motherboard with the PCIe 5.0 will be highly beneficial and future-proof. 

Recently, the PCIe 6.0 has also been announced and its specs have been released. But it will not come to market sooner and 5.0 will be used widely for a few years. Also, 5.0 will not become obsolete even after the introduction of 6.0 or future generations due to the availability of forward and backward compatibility.

With the latest gen PCIe, you will be able to use the hardware with the maximum performance it can provide and with higher efficiency. The power consumption will also be very less and even if the device is upgraded to a higher generation, the slot will not become outdated. It can perform well with the same efficiency and effectiveness.

The difference between a 4.0 and 5.0 PCIe slot is twice in all aspects. Except for the lane configuration which is from x1 to x16, the performance is faster than the previous generations of the PCIe slot.

So, using a PCIe 5.0 with 4.0 or vice versa is not an issue. Even though they have different levels of performance, they can be easily used on one another despite their generation. 

Read: Can I use PCIe 4.0 SSD in 3.0 slot?

Does it affect the performance of your PC?

Using higher gen hardware with a lower gen slot will affect the performance of the hardware. That means the performance will depend on the capacity of the lowest gen between slot and hardware. You cannot see any boost in the performance of your PC when you are using it in such a fashion. Also, sometimes you can experience bottlenecks during heavy usage. 

But on the other hand, using 4.0 hardware in a 5.0 slot will not produce any bottlenecks or downgrade in performance. Rather, you can have the maximum performance of the 4.0 without any issues. 

Before buying a hardware with PCIe interface, it is important to check for two major things:

  • Lane Compatibility
  • Generation

As for the generation, we know that they are compatible both ways. But to get the maximum performance of the hardware, you need to have the same gen or higher gen slot.

But lane compatibility is a must and you cannot connect the hardware without checking it. If you are having hardware that requires an x8 lane, you need at least a PCIe x8 or higher. You cannot connect it to an x4 PCIe slot.

Therefore, the performance of the PC will be affected only in the following circumstances:

  • When you use a higher generation PCIe hardware to a lower generation slot, the hardware will perform to the specification of the slot which might create a bottleneck.
  • When you don’t check out the lane configuration and use it, you may have some performance issues.
  • Using very old hardware or PCIe slot can lead to lower performance in your PC.

Only with the above-mentioned situations, you can have a lower performance on your PC. Otherwise, mismatching the PCIe slots with different generations doesn’t affect the system in any way.

Read: Do GPU risers need power?


A PCIe interface is the standard for connecting heavy hardware like GPU to the motherboard which in turn communicates to the CPU through it. With the latest generation PCIe slot, you can have faster communication, better performance, and increased efficiency with higher speed. You can easily upgrade the hardware you are using and get a higher performance on your PC. 

The latest 5.0 PCIe can be used with a 4.0 and vice versa is also possible. But you can have some slight downgrade in performance when you use 5.0 hardware with a 4.0 slot. Therefore, looking after such criteria before buying a device can help you to get the best performance for your system.

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