read my post I made 2 days ago here
https://forums.macrumors.com/threads/530205/
it explains alot.
In the end, I think I am just keeping it ( i DO believe these conditions and readings we are seeing, are normal for the latest MacPro revision).
The only way to alter the PSU fan speed that I've found is to compile some crazy code in Xcode.
The main thing that matters is Ambient temps inside the computer to change the PSU fan, just try to keep it cool around the computer(which is what I have done).
I see improvements but my constant is 68/60, and I have seen it go as high as 80/70.
I think its normal for this new powersupply, also does your click when you plug a live cord into it?
Read my post and get back to me asap.
Thanks