PSU Fan Run Fast.

Hey,
So after spending a week or so fixing my motherboard and reinstalling it with a brand new better power supply.. I find that my power supply fan is running unusually fast around 3000RPM... I don't know if it is supposed to go that fast or if something is wrong.. Kinda weird though because my old PSU ran quieter and was not as good a power supply.

Old PSU: Corsair HX620W Professional Series
New PSU: Corsair AX650W Gold series.

So if anyone has any ideas or just to tell me that it is normal that would be great.
Thanks.

MHWadester,
The first thing I would worry about is if the new PSU is getting ample air supply but it's new and likely has the same orientation as the original (please confirm this) meaning that it's fan intake is the same as the original. If so then I would contact Corsair or where you purchased this and begin an exchange or RMA as there is zero reason for any new PSU to run at this high fan speed.
If you have a digital camera could you provide pictures of PSU and all connections to mobo and graphics card(s).