The
i9-9900K is based on
Coffee Lake architecture while the
906ED 2.1GHz is based on
Comet Lake.
Using the multithread performance as a reference, the i9-9900K gets a score of
545.3 k points while the 906ED 2.1GHz gets
657.2 k points.
Summarizing, the
906ED 2.1GHz is
1.2 times faster than the
i9-9900K. To get a proper comparison between both models, take a look to the data shown below.