Large voltage drop at card, room for concern?

[1slickvdc]

I'm running dual GTX 760's in SLI, (along with an MSI Z97 board and an i5 4590, among other things) and I've noticed during benchmarking and monitoring that it was throttling due to VREF. So I took a meter to the PCIe power connection at the card and I'm noticing a shift in the voltage, what seems to me to be significant. At idle it reads 12.10V, but under heavy load, it drops to ~11.85-11.90.

Hell, I figured a 750W supply would have been enough. Maybe not? Figured I'd ask before I go and spend money I almost don't have on a different PSU.

 

[smorizio]

every power supply as long as it runs between these sets of numbers are fine.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CEUQFjAA&url=http%3A%2F%2Fwww.formfactors.org%2Fdeveloper%2Fspecs%2FATX12V%2520PSDG2.01.pdf&ei=C6hyVPaUM8L-yQT2zYG4CQ&usg=AFQjCNGyaiGxTJEv9ctY5MBszk75q4-unQ&bvm=bv.80185997,d.aWw&cad=rja

with some units have better parts and design like the cosair and seasonic units. if the unit starts to drop lower or your withing your 30 days i rma and get a better unit.

 

[1slickvdc]

I was more wondering what the card's tolerance is.... is it designed specifically for 12.0 and above, or will under 12.0 cause it to not quite get as much, or... since voltage drops are usually indicative of reaching a current limit of SOMETHING in the chain, could it be that the PSU is just not powerful enough?