PCIe (Peripheral Component Interconnect Express) has become the standard interface for connecting peripherals to a computer's motherboard. With the rapid advancement of technology, PCIe has undergone significant improvements, resulting in faster data transfer rates and increased bandwidth. In this article, we'll delve into the world of PCIe, exploring its generations, features, and what you need to know when choosing a PCIe expansion card.
What is PCIe?
PCIe is a high-speed interface that allows devices such as graphics cards, hard drives, and solid-state drives (SSDs) to communicate with the motherboard. It's an open standard that has become ubiquitous in modern computing.
PCIe x1, x2, x4, and x16: What Do They Mean?
The number after the "x" in PCIe refers to the number of lanes available on the slot. A PCIe x1 slot has one lane and can move data at one bit per cycle. A PCIe x2 slot has two lanes and can move data at two bits per cycle, and so on.
Can You Mix and Match PCIe Cards?
Yes, you can insert a PCIe x1 card into a PCIe x16 slot, but the card will receive less bandwidth. Similarly, you can insert a PCIe x8 card into a PCIe x4 slot, but it'll only work with half the bandwidth compared to if it was in a PCIe x8 slot.
Most GPUs Require a PCIe x16 Slot
Most graphics processing units (GPUs) require a PCIe x16 slot to operate at their full potential. This is because GPUs need a dedicated connection with the motherboard to handle the high-speed data transfer required for gaming and other demanding applications.
PCIe Generations Compared
| Generation | Bandwidth | Frequency |
|---|---|---|
| 1.0 | 8 GB/s | 2.5 GHz |
| 2.0 | 16 GB/s | 5 GHz |
| 3.0 | 32 GB/s | 8 GHz |
| 4.0 | 64 GB/s | 16 GHz |
| 5.0 | 128 GB/s | 32 GHz |
Current PCIe Generations
There are currently five different generations of PCIe standards: PCIe 1.0, PCIe 2.0, PCIe 3.0, PCIe 4.0, and PCIe 5.0. Each generation offers double the bandwidth of the previous one.
How Do You Know What Performance You'll Get?
When choosing a PCIe expansion card, you need to consider the generation of the slot on your motherboard. Your PCIe card will run at the lowest generation present. For example, if you put a PCIe 2.0 card in a PCIe 3.0 slot, you'll get PCIe 2.0 performance.
PCIe 4.0: The Latest Generation
The PCIe 4.0 standard debuted in 2017 and offers 64 GBps of throughput. It's available for enterprise-grade servers but only became usable with SSDs in 2019. The AMD Ryzen 3000-series CPUs that debuted in July 2019 were the first desktop CPUs to support PCIe 4.0 x16 out of the box.
PCIe 5.0: The Future of High-Speed Connectivity
The official PCIe 5.0 standard came out in May 2019 and will bring 128 GBps of throughput. It's backward compatible with previous PCIe generations and includes new features such as electrical changes to improve signal integrity and backward-compatible CEM connectors for add-in cards.
PCIe 6.0: The Next Generation
In June 2019, PCI-SIG announced that it would release the standards for PCIe 6.0 in 2021 (the spec is currently in revision 0.7). We don't expect to see products until at least the end of 2022, if not 2023.
PCIe 6.0: What's New?
PCIe 6.0 will double the bandwidth of PCIe 5.0 to 256 GB/s among the same maximum number of lanes (16). Data transfer rate will hit 64 GT/s per pin, up from PCIe 5.0's 32 GT/s. PCIe 6.0 is also expected to be backward compatible with previous PCIe generations.
PCIe has become an essential component in modern computing, enabling high-speed data transfer and connectivity between devices. As technology continues to evolve, PCIe will likely continue to improve, offering faster speeds and increased bandwidth. When choosing a PCIe expansion card or motherboard, it's essential to understand the different generations and their capabilities to ensure you get the performance you need.
Further Reading
- Dissecting the Modern Motherboard: Connectors, Ports & Chipsets Explained
- How to Choose a Motherboard
- Best Motherboards