SeanPoe has posted an excellent guide on overclocking the GTX 670 which should also be applicable to the 690. Give it a look and see if it helps.~~The GTX 670 Overclocking Master-Guide~~
Edited by BulletSponge - 3/10/13 at 2:48pm
The Power Percent is the percent of TDP (Thermal design power) the card is running at. So if the card's TDP is rated at 170W and the card is running at a Power Percent of 117%, that means it's drawing 17% more watts of power than TDP, or 199W. The Power Target on the other hand, is a user defined number that tells the GPU how much over TDP it can go. For example, if you were to set the Power Target to 109% then the card would be able to run about 9% over TDP. However, there does seem to be some additional headroom involved, so realistically, a 109% Power Target would allow the card to go up to around 115% Power Percent. Like i mentioned above in the Kepler Boost section, Kepler Boost is also throttled down based on Power Percent. If the GPU is set at 100% Power Target, then the card will only be allowed to draw enough power to boost up to ~100% of TDP, anymore than that and the card will start to throttle the Kepler Boost value by 13Mhz increments in-order to stay below this number. If you were to then set the Power Target to a higher value, then the GPU could boost a little higher until it either reaches its maximum Kepler Boost or it reaches this new Power Target.