Recently, we have received a few Lenovo X390 laptops that have an issue where CPU performance was abnormally low.
The base CPU rate of X390 is 1.9Ghz. And usually should burst to about 4Ghz when running business apps.
Some Lenovo X390 experienced issues where the CPU performance was running at 0.6-1.2Ghz.
After check with Lenovo Support, we were advised to upgrade the bios above 1.70 one which was released on September 2020.
You can download the X390 BIOS use the link below.
Also a good idea to install the Lenovo Updater 5 and ensure the Laptop is up to date.