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 goal is to transfer enough data to saturate the PCIe 4.0 interface.
The result of the test is the average bandwidth achieved during the test.
As I am sure you are aware, this test is based on a synthetic scenario. 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 and 3DMark Professional Edition.
You need a DirectX 12 compatible discrete graphics card to run the 3DMark PCI Express feature test. The test will not run on systems that only have integrated graphics. In multi-GPU systems, the test will run on the primary GPU. External GPU enclosures are not supported.
The amount of bandwidth available over PCI Express will depend on your motherboard, your graphics card, the PCIe slot used by your graphics card, your system's BIOS settings, and other factors.
You can find more details in the 3DMark technical guide.