The
G645 is based on
Sandy Bridge architecture while the
5405U is based on
Whiskey Lake.
Using the multithread performance as a reference, the G645 gets a score of
35.4 k points while the 5405U gets
48.8 k points.
Summarizing, the
5405U is
1.4 times faster than the
G645 . To get a proper comparison between both models, take a look to the data shown below.