PCIe Gen4 is the fourth generation of the PCI Express specification. As the subsequent iteration of Gen3, Gen4’s data transfer rate is twice that of PCIe Gen 3, enabling PCIe Gen 4 devices to transfer data at a faster speed. PCIe Gen3 operates at a data transfer rate of 8 GT/s (gigatransfers per second), which translates to roughly 1 GB/s (gigabits per second) per PCIe lane. In comparison, PCIe Gen4 operates at 16 GT/s, converting to about 2 GB/s per PCIe lane.

When building PCs, more and more people are choosing M.2 NVMe SSD data storage devices. However, consumers will encounter a dilemma when actually selecting parts. What is the difference between Gen4 and Gen3? Why is there such a large price difference?

Put simply, imagine there are 8 vehicles running on a highway and each vehicle is carrying data. If the number of lanes is doubled, then the highway can accommodate 16 vehicles which equates to transmitting twice the data volume.

PCIe devices use "lanes" to transmit and receive data, so the more lanes a PCIe device can use, the greater the bandwidth (the wider the highway). Generally speaking, the number of lanes supported by a PCIe device is represented as follows: "x4" means 4 lanes, and "x8" means 8 lanes. Taking the ADATA LEGEND 960 MAX as an example, this SSD is PCIe Gen4 x4.

Now, the question becomes: “Is there an obvious difference in real-world situations?” With improvements in graphics card specifications driving the advancement of game and movie technology, the PCIe bandwidth of previous-gen motherboards will soon be saturated. The emergence of PCIe Gen4 allows users to achieve the same or even better performance with fewer lanes and improve the expandability of motherboards. Loading and transmission of large files are also significantly accelerated, greatly reducing wait time.

Incidentally, new generation flash memory technology has neatly resolved the capacity vs. price issue, which means that PCIe Gen4 SSDs can offer more capacity. For players who value performance and capacity, PCIe Gen4 SSDs are the obvious choice.