Nice clocks, especially the ram. Max volts imo depends on your cooling, its really limited by temperature, until you reach the OVP level which is usually encountered after setting 1.44 - 1.45v idle. If you did the OVP mod too, perhaps up to 1.5v would be ok, as imo the PWM on the card would be reaching its limit between 1.5 & 1.7v. I'd recommend the HIPRO5 coil & cap mod if you want to go over ~1.6v