Well.... my problems are solved!!!!.
What I do?.
I disabling the first card... (remove with switch on RIVE).
I try the second (stock BIOS)... I have been surprised!!!. At this form I can adjust voltage in Precision...MMmmmm
Well, second step... I have re-enabled SLI...
Ta-chan!!!. It was my fault! --> Voltage in Precision (although both cards are synchronized are independent!!!, With the right mouse button you must select the voltage for each....
After that, I've been much "in peace"... and I decided to put the TI BIOS....(flashed both card - 0 problem). Since this moment I was with stock BIOS.
Not more Throttling (although I have very minor....).
Well, at this point I´m trying with 1.162v on First GPU (71%) and 1.187 at the second (voltage raise automatic for this at this Offset)
Both cards, for now are at 1137 boost....
I´ll try with max voltage 1.212 but about 1180 on core Unigine Crash (I think which is due to Second GPU); so I prefer saving "voltage"....
The next step is to try to climb (without sync) the first gpu.
Thanks at all!!!.