Bit Tech received a statement from NVIDIA on the matter:
In a statement, Nvidia explained that ‘in the web release driver of GeForce GTX 590, we have added some important enhancements to our overcurrent protection for overclocking. We recommend anyone doing overclocking or running stress apps to always use the latest web driver to get the fullest protection for your hardware.’
The company also stressed that the card is completely safe, saying that customers could 'rest assured that the GTX 590 operates reliably at default voltages.' You can see a video of the GTX 590 3GB failing below, although Nvidia claims that the damage was caused by a user overvolting the card's GPUs by as much as 1.2V; a huge increase over the default voltage of 0.91 to 0.96V.
However, Nvidia still recommends that overclockers play it safe with the voltage, even if they're using water-cooling. ‘Nvidia has worked with several water-cooling companies to develop waterblocks for GTX 590,' says the company, 'and these solutions will help provide additional margin for overclocking, but even in this case we recommend enthusiasts stay within 12.5-25mV of the default voltage in order to minimise risk.’