The
G645 is based on
Sandy Bridge architecture while the
Q8400 is based on
Core.
Using the multithread performance as a reference, the G645 gets a score of
35.4 k points while the Q8400 gets
51.9 k points.
Summarizing, the
Q8400 is
1.5 times faster than the
G645 . To get a proper comparison between both models, take a look to the data shown below.