Originally Posted by Bman212121
I'd like to see someone throw a clamp meter around the cables though... The HD6990 was supposed to be pushing the limits of the PCI-E spec and the GTX 590 draws another 45W beyond that. Just make sure you have some pretty hefty rails going to that GPU and you will probably be okay.
It is quite amazing what Nvidia was able to do with the cooler. Given the temps are in the same range the card is quieter while drawing more power. What I think happened was Nvidia was making a cooler designed for a higher TDP and they decided to lower the clocks and bring the power level down some. This obviously hurt the performance but it helped the noise levels.
EDIT: Hmm I'm seeing numbers all over the place. Some claim lower, some higher. It would matter which profile people were using for the AMD card though. Nvidia lists the card as 365W TDP so that keeps it in spec. There might be some headroom to overclock the card if you turn the fan to manual.
I'll quote myself...
To answer my own question anandtech has a nice little blurb that most likey has something to do with this.
At this point our biggest complaint is that OCP’s operation is still not transparent to the end user. If you trigger it you have no way of knowing unless you know how the game/application should already be performing. NVIDIA tells us that at some point this will be exposed through NVIDIA’s driver API, but today is not that day. Along those lines, at least in the case of Furmark and OCCT OCP still throttles to an excessive degree—whereas AMD gets this right and caps anything and everything at the PowerTune limit, we still see OCP heavily clamp these programs to the point that our GTX 590 draws 100W more under games than it does under Furmark. Clamping down on a program to bring power consumption down to safe levels is a good idea, but clamping down beyond that just hurts the user and we hope to see NVIDIA change this.
Anyone who used Furmark for their power tests will not have valid results as the OCP will go out of it's way to throttle the program. That's also going to skew temperatures considerably as it's drawing a lot less power.