https://wccftech.com/amds-radeon-rx-5500-xt-graphics-cards-bottlenecked-by-pcie-bandwidth/

With the recent release of the RX 5500 XT, AMD filled out the lineup of its graphics stack, bringing real competition to the budget GPU market. One of the new features that the Navi GPU featured on the RX 5500 XT is the support for PCIe 4.0 but while we haven't seen any real-world benefits as of yet, PCGamesHardware has put the card to the test and found out that PCIe 4.0 may not be the gimmick that everyone has perceived it to be.

In testing performed by German website PcGamesHardware.de, the results show that while the 4 GB variant had noticeably lower performance than the 8 GB variant in the few titles tested, switching over to the PCIe 4.0 delivered much more consistent frame times, offering a more playable experience than what was capable on PCIe 3.0 interface.