"IBM came to AMD for help"
I don't think anyone has ever made that particular claim, I certainly never have.
As I have pointed out before, PPC970 has a 16 stage pipeline and will top at 2GHz on their 130nm process, AMD can do at least 1.8GHz on their 130nm process. Ok, you can't really compare the two processors straight up, but you'd generally expect a processor with close to twice the number of pipeline stages to clock a bit higher, assuming roughly the same amount of work per stage.