I bought the new Samsung 980 Pro 1TB (PCIe 4.0) and put in the Lenovo Yoga Slim 7 (PCIe 3.0), I saw only ~10% decrease in raw performance : r/AMDLaptops
Samsung SSD 980 Pro Review: Blazing Fast PCIe 4.0 Storage | HotHardware
Samsung 980 Pro review | Rock Paper Shotgun
Samsung 980 Pro review: A beast mode upgrade for your PC or PS5 | Windows Central
1TB SSD 980 PRO PCle 4.0 NVMe M.2 | Samsung Australia
980 PRO | Consumer SSD | Samsung Semiconductor
Samsung finally launches 980 Pro, its first PCIe 4.0 NVMe consumer SSD - SamMobile