Q:
tell me the compatibility problem about Core i7 620um and ubuntu 20.04, and the solutions if exist

A:
The Core i7 620UM processor is a relatively old processor that was released in 2010. While it is possible to install and run Ubuntu 20.04 on a system with this processor, there may be some compatibility issues that you may encounter.

One potential compatibility issue is related to the kernel version used by Ubuntu 20.04. The Core i7 620UM processor uses the Arrandale microarchitecture, which is quite old. Some of the features in this microarchitecture may not be fully supported by the newer kernels used by Ubuntu 20.04. This may result in stability issues or reduced performance.

Another potential compatibility issue is related to graphics drivers. The Core i7 620UM processor uses integrated Intel HD graphics. While Ubuntu 20.04 does come with drivers for Intel HD graphics, these drivers may not be optimized for the specific graphics hardware in the Core i7 620UM. This may result in poor graphics performance or graphical glitches.

If you encounter these compatibility issues, there are a few potential solutions that you could try:

Use an older version of Ubuntu that is more compatible with the Core i7 620UM processor. For example, Ubuntu 16.04 LTS may work better on this processor, as it uses an older kernel and may have better support for the Arrandale microarchitecture.

Install a different Linux distribution that is better optimized for older hardware. For example, lightweight distributions like Xubuntu or Lubuntu may work better on the Core i7 620UM.

Try installing newer or alternative graphics drivers. For example, you could try installing the Intel Graphics Update Tool for Linux, which may provide more up-to-date drivers for the integrated Intel HD graphics.