Atto performance on ASRock Z77 Extreme4 versus ASRock Z97 Extreme6

I just purchased two Sandisk Extreme Pro 240GB SSD’s.  Very impressed with the Atto preformance results.  However, I have one “problem” where the Atto results for 0.5 - 16.0 are much lower (slower) on the Z77 versus the Z97 system.  By slower, I mean the 16.0 Read performance is only ~182,000 on the Z77 system and ~504,000 on the Z97 system.  For some reason the 16.0 results are the worst by a factor of 2 or 3!  I have run the Atto test multiple times and the results do not change.  I took the SSD on the Z77 and installed it on the Z97 and it performed “normally” meaning the results were outanding.  So…it ain’t the SSD that is causing the “problem”.  Is there something about the Z77 chipset/drivers that is causing the issue?  Both systems are running W8.1 and have the same software except for the Z77 vs Z97 SATA drivers. 

I would post the Atto screen shots but I can’t figure out how to do it on this site.  There is a thread on the Tweaktown/ASRock forum that has all the Atto stuff.  If someone can give me a little help on how to post the screen shots on this site  I would appreciate it.