New Mac Pro and 9.2 Hangs on Adjustments?? Old G5 Doesn't

Question

Hello
I have what should be a very fast new Mac Pro.  6 core at 3.46Ghz.  48Gb of RAM.  Solid state boot drive.  Software RAID 0 with 2 Hitachi 3TB drives, hardly anything on them yet. Nvidea Quadro 4000 CUDA card.  Everything installed and burned in for the overnight 8 hour test with the MPG workstation program at OWC.  Lion 10.7.2.
I had approximately 700 in camera photos combined still in camera between an up-to-16MP Sony NEX 5N camera and up-to-24MP pics on a Sony A77, that have already been loaded into my 6-7 year old 2.4Ghz dual core G5 with 6.5Gb RAM and much older version of iPhoto. OS 10.4.7 I believe. 
Last night I loaded all those same pictures into the new machine and 9.2 version iPhoto.  And then deleted them from the cards on both cameras.  No issues. Smoking fast imports compared to the G5 which wasn't all that bad.
On the G5 with the picture adjust controls I could use the slider to go deeply into those same photos and see the effects of contrast, sharpness and all the other options.  Like butter.  Make the adjustments while in that deep if desired and then pull back to evaluate the overall picture before saving.  Or back in again if desired. No issues.
With the new rig I couldn't wait to try all of this, but once I go deep inside and start to move the adjustment slider controls the system every time starts getting hung with the spinning wheel.   Have to wait and wait for them to catch up to the curser on that adjustment.  Most of the time the system then will just get stuck and I have to force iPhoto to quit.
Please....does anyone know why all this latest powerfull hardware and software is doing that, compared to the old, much less capable G5?  I am really concerned now.  Haven't had a chance to get Photoshop and the other production premium software tested yet.
And one last question please.  Does anyone know if the "Enhance" feature in the Quick Fixes section adjusts Gamma as well?  There seems to be a lot more going on to give the photos depth (what I always really try to do)   than the sum of the small slider movements in the Adjust section.  With my old system and iPhoto version there was no "Gamma" adjust slider in iPhoto proper......but if I saved a photo first to my Desktop for instance, and then called up the adjustment features, there was a Gamma slider there.  Very handy and appreciated.
I see similar vast improvements on some photos now with the "Enhance" feature that looks like maybe Gamma has been optimized as well?  There now is no Gamma slider available even if the photo is taken to the desktop first.
Thanks much
Ron

Answer 1

Hello Terence
Thanks for the tip to try.  Couldn't get to it until late last night.  Seems to still be the same in Library 2.
Also seems to be worse with 27" Cinema Display at full resolution.  And with several sliders on adjustment.  If I drop the resolution to 1920 x 1080 or 1600 x 900 and move smoothly about it is not as apt to hang up.  With as much horsepower as the new Mac Pro has, should resolution of monitor be an issue in these adjustments deep into the pictures?
How about the Enhance button?  Is gamma involved?  Everything I read about it on searches only talks about boosting saturation of the color and fine tuning with little other slider adjustments.  But on a picture where it has made a big difference to the good with depth and overall look, if I look at where the sliders were adjusted and then undo the enhance, and go back and manually put the sliders in the same position it doesn't look the same.
Does anyone know if gamma is being adjusted with this button?  Sure seems like it but can't find it mentioned anywhere.
Thanks again!