SLI GTX 560 voltage problems

I have a pair of GTX 560's running in SLI and the top card never drops the voltage level when idling but the bottom card does.  Anyone know how to make both cards do this?  Would be great as one card is always running hotter than the other. 

Any responses will be greatly appreciated.

 

if you have a second monitor connected to the first card some cards do not drop the clocks on idle you could try pluging your second monitor into the second card if you have one.  Other wise it could be that UPLS power saving is disabled.