One of the exciting things that AMD's third-generation Ryzen processor family and accompanying X570 chipset will usher in is support for PCI Express 4.0. This offers double the bandwidth of PCI Express 3.0, paving the way for faster graphics and speedier storage drives. To help measure the impact that PCie 4.0 can have, UL Benchmarks is adding a new test to its 3DMark suite.
It's actually a PCI Express feature test, meaning users will be able to run it on any modern platform, including existing PCie 3.0 motherboards. Users who dive into a newfangled Ryzen setup using the latest processors and motherboard options, however, will obviously see a better benchmark score, for whatever that is worth.
"3DMark feature tests are specialized tests for specific technologies. The 3DMark PCI Express feature test is designed to measure the bandwidth available to your GPU over the PCIe interface. It will help you compare bandwidth across PCIe generations with a test that's quick and easy to use," UL Benchmarks explains.
It's not yet clear how exactly the test will measure performance. We already know that PCIe 4.0 is the fastest shipping version of the protocol, at least until manufacturers adopt the newly ratified PCIe 5.0 spec. Here's how they different versions compare...
- PCIe 5.0: 32GT/s transfer speed, 128GB/s bandwidth
- PCIe 4.0: 16GT/s transfer speed, 64GB/s bandwidth
- PCIe 3.0: 8GT/s transfer speed, 32GB/s bandwidth
- PCIe 2.0: 5GT/s transfer speed, 16GB/s bandwidth
- PCIe 1.0: 2.5GT/s transfer speed, 8GB/s bandwidth
We do not need a specialized benchmark to tell us those figures, as we already know the theoretical maximums. We suppose the benchmark will test how well a particular motherboard implements whatever PCIe protocol it is using, with a slant towards graphics.
In terms of real-world performance, we will have to wait and see how things shake out with PCIe 4.0 on X570 motherboards, versus PCIe 3.0. We have already seen some new PCie 4.0 SSDs touting speeds of up to around 5,000MB/s, but real-world graphics performance (as it pertains to gaming) might be negligible.
We will know more in July when AMD's new stuff starts shipping. As for the PCI Express feature test, it will be added to 3DMark sometime this summer as a free update to both the Advanced and Professional editions.