Recently, I built a new computer with ASRock J3455-ITX which has a Apollo Lake processor build-in to run Force.com IDE and VisualStudio Code. I have to use OpenSuSE Tumbleweed to replace my favorite Leap because it requires the latest kernel to support Apollo Lake.
Everything seems fine but it becomes very slow after resume / suspend. I have tested many power-related settings in UEFI (Unified Extensible Firmware Interface) and none of them help. If I logout GNOME and login again, I regain my normal speed.
I try to google “linux slow after resume” and found some useful information. It seems related to
Doug Smythies and jat255 provide detail explain and a solution to restore CPU frequency as a service in Slowdown after resume from suspend on ArchLinux.