New Mac Pro 6.1 slow for some tasks, any ideas?

Question

May new Mac Pro 6.1 (6 core, 64 GB RAM, D700's) is running very slow for 2 specific tasks.
OS X 10.9.3  PS CC 14.2.1
Open Canon 5D3 Camera Raw files takes 30 seconds.
Smart Sharpen 5D3 file takes 75 seconds.
That is WAY slower than my 6 year old Mac Pro 3.1!
Everything else runs quickly and efficiently on the 6.1, but it almost freezes during these 2 tasks.  Not good!  As a photographer who processes hundreds of 5D3 RAW files at a time this is a big problem for me.
I found this article explaing issues with the graphics;
http://macperformanceguide.com/blog/2014/20140308_1-Photoshop-sharpening-speed.html
However my performance is way worse than reported here.
I hope to find a solution...

Answer 1

Thanks for your input Noel.
I have unchecked Use Graphics Processor and the time for opening a RAW file remains around 30 seconds and to smart sharpen is now 100 seconds (up from 75).
In the activity monitor, I get between 500 and 600% use of the processors when opening RAW and 800% during sharpening.
A few seconds after clicking open in ACR, I get a dialogue box with the blue bar almost complete for a fraction of a second, then it disappears and another box appears (half the hight of the first one) and starts with only a small part completed, then takes it 30 seconds to finish.  It's like it tried to open in a normal way and failed, then another very slow backup process took over.
In the top righ corner of the Smart Sharpen dialogue box, I tried selecting "Use Legacy", then it sharpens in about 3 seconds!
Also of note, when opening a RAW file or smart sharpening, the computer becomes very slow and unresponsive, even to get mail or surf the internet.  Even streaming radio in iTunes cuts in and out or cuts out completely.  As if the entire system is overwhelmed.  Despite having 2 or 3 cores unused and at least 40 GB of unused RAM.
Not what I was expecting from a very expensive upgrade in the hopes of cutting down the amount of computer time per image file!