We're adding a new feature test to 3DMark today in anticipation of upcoming hardware that will support the next-generation PCI Express 4.0 interface.
3DMark PCI Express feature test
PCI Express (PCIe) is a standard interface that provides high-bandwidth communication between devices in a computer. Next-generation PCI Express 4.0 interfaces provide up to twice the bandwidth of PCI Express 3.0. With more bandwidth, games can transfer more data, reduce loading times, and support more complex scenes. The first motherboards and graphics cards to support PCIe 4.0 are expected to arrive this summer.
3DMark feature tests are special tests designed to highlight specific techniques, functions or capabilities. The 3DMark PCI Express feature test is designed to measure the bandwidth available to your GPU over your computer’s PCI Express interface.
The test aims to make bandwidth the limiting factor for performance. It does this by uploading a large amount of vertex and texture data to the GPU for each frame. The result of the test is the average bandwidth achieved during the test.
https://www.youtube.com/watch?v=UhCT-Tdp-_w
In real-world use with today's rendering pipelines, a PC’s gaming performance is unlikely to be limited by PCIe bandwidth. Nevertheless, the increase in bandwidth that PCIe 4.0 brings is sure to open up new possibilities with future hardware.
The 3DMark PCI Express feature test offers an accurate and reliable way to compare bandwidth across PCIe generations and measure the performance of different hardware configurations.
The PCI Express feature test is available now in 3DMark Advanced Edition.
https://store.steampowered.com/app/223850/3DMark/