For the past decade, PCIe has been the standard interface for connecting high-speed peripherals to computer motherboards. The fourth generation of this standard, PCIe 4.0, was released in 2017. However, it wasn't until Computex 2019 that we saw SSDs or graphics cards that took advantage of this new technology. Today, PCIe 4.0 has ushered in a new wave of innovation in this technology, with products such as SSDs, GPUs, motherboards, or high-performance expansion cards. But what is PCIe Gen 4? We'll break down the basics.
What is PCIe Gen 4?
PCIe Gen 4 is the fourth generation of the PCI Express specification and is the latest generation available. As the successor to PCIe Gen 3, PCIe Gen 4 is the fastest PCIe specification currently on the market.
What does PCIe Gen 4 do?
PCIe Gen 4 allows systems to connect to high-performance PCIe devices such as GPUs and PCIe NVMe SSDs.
Is PCIe Gen 4 necessary?
Advances in PCIe technology help meet the growing demand for high-speed data buses to support increasingly demanding user applications and workloads.
What is the difference between PCIe Gen 3 and PCIe Gen 4?
PCIe Gen 4 has twice the data rate of PCIe Gen 3, allowing PCIe Gen 4 devices to transfer data much faster. PCIe Gen 3 runs at 8 GT/s (Gigatransfers per second), which roughly translates to 1 GB/s per PCIe lane. PCIe Gen 4 runs at up to 16 GT/s, which roughly translates to 2 GB/s (Gigabytes per second) per PCIe lane.
What is the maximum bandwidth of PCIe Gen 4?
In order to understand the maximum bandwidth of a PCIe Gen 4 device, you must understand the maximum number of PCIe lanes supported by the device. PCIe devices use "lanes" to send and receive data, so the more lanes a PCIe device can use, the higher the bandwidth possible. The number of lanes supported by a PCIe device is usually expressed as: "x4" for 4 lanes, "x8" for 8 lanes, and so on.
|
x1 |
x2 |
x4 |
x8 |
x16 |
| PCIe Gen 3 Bandwidth |
1 GB/sec |
2 GB/sec |
4 GB/sec |
8 GB/sec |
16 GB/sec |
| PCIe Gen 4 Bandwidth |
2 GB/sec |
4 GB/sec |
8 GB/sec |
16 GB/sec |
32 GB/sec |
Is PCIe Gen 4 backward compatible?
PCIe Gen 4 is backward compatible, so a PCIe Gen 4 device connected to a PCIe Gen 3 system will run at PCIe Gen 3 speeds. This means that if you buy a PCIe Gen NVMe 4 SSD today, you can use it immediately in your system, even if your current system does not support PCIe Gen 4. If you upgrade to a PCIe Gen 4 system in the future, you can unleash the full performance of your PCIe Gen 4 NVMe drive.
When will PCIe Gen 4 be available?
PCIe Gen 4 is currently being adopted by the industry, and many PCIe Gen 4 products are now available, but only the newest products support PCIe Gen 4. In the future, PCIe Gen 4 will become the industry standard.
How to use PCIe Gen 4?
To take full advantage of PCIe Gen 4 PCIe Gen 4, your CPU, motherboard, and PCIe devices must all support PCIe Gen 4.
What desktop platforms currently support PCIe Gen 4?
Desktop CPUs and motherboards that support PCIe Gen 4 and are currently available include:
>AMD Ryzen™ 3000 and 5000 series CPUs
>AMD X570, B550, and TRX40 motherboards
>Intel® 11th Generation "Rocket Lake" and 12th Generation "Alder Lake" Core CPUs
>Intel® Z490, Z590, and Z690 motherboards
What is PCIe NVMe?
PCIe NVMe SSDs are SSDs that use the high-speed PCIe bus for data transfer and the NVMe (Non-Volatile Memory Express) protocol to communicate with the host system. Compared to SATA SSDs, PCIe NVMe SSDs are more efficient than SATA SSDs. These drives running on the bus offer significantly increased bandwidth and responsiveness.
Will PCIe Gen 4 make PCIe NVMe SSDs faster?
PCIe Gen 3 cannot support the full bandwidth of high-speed PCIe NVMe SSDs. This effectively creates a performance bottleneck for SSDs. PCIe Gen 4 removes this performance bottleneck, allowing PCIe NVMe SSDs to read and write data much faster.
What form factors does PCIe NVMe use?
PCIe NVMe SSDs are available in a variety of form factors, such as Add-In-Card (AIC), M.2, and U.2. Client PCIe NVMe SSDs are typically available only in the M.2 2280 form factor, which is thinner and easier to fit into desktops and laptops. Enterprise PCIe NVMe SSDs use all three form factors, with U.2 being the most popular due to its compatibility with server backplanes.
Conclusion
The PCIe 4.0 platform allows for greater flexibility and available bandwidth. SSDs that utilize PCIe 4.0 are perfect for data-intensive workloads. Not only will apps and games load faster, but boot speeds will also be optimized. PCIe 4.0 also introduces power-saving enhancements, meaning your device will run cooler and consume less power. As more products adopt PCIe 4.0, choosing between PCIe 3.0 and 4.0 will be simple. Even before you know it, PCIe 4.0 will be the industry standard.
