How to fix texture flickering in Hitman 3 on A620M?

Switching levels in Santa Monica caused annoying texture flickering. I tried BIOS tweaks, but GPU failed. Using GamePP Hardware Sensor Page, I set PCIe to Gen 3. Bandwidth rose from 12GB/s to 15-16GB/s per 3DMark. GPU temp stayed at 62-68℃ per HWiNFO, and load times dropped to 3s, finally fixing the artifacts.