That is clocked at 800 MHz. A repository at this size deserves a
better CPU. At 2.5 GHz we spend 183.228ms on loading the index. A
reasonable number to me. If we scale other parts of git-status as well
as this, we should be able to make "git status" within 1 or 2 seconds.

Which harddrive do you use? Traditional or SSDs?
Does have harddrive loading time significant impact here? (just a
guess/question)