According to the latest rumours, the GTX 590 won't be anywhere close to the GTX 580 specs, at least when clocks are concerned. Apparently, the GTX 590 GF110 cores will work at around 600MHz.
Bear in mind that specs are coming from various sources and nothing has still been confirmed by Nvidia, but it looks like GTX 590 will end up clocked at around 600MHz for the GPU. Those 1024 CUDA cores, or simply shaders, will end up at around 1200MHz, while the memory should be set at around 3400MHz and paried up with a 2x384-bit memory interface. The reference GTX 580 was working at 772MHz for the GPU and 4008MHz for memory.
Not straying from its tradition, Nvidia is still talking about "average TDP" which will be set at around 375W for the GTX 590. It needs two 8-pin PCI-Express power connectors, and in case you are wondering, the average TDP for the GTX 580 was 244W. Once again, Nvidia is also talking about noise, and we must say that the card was pretty quiet, at least the one seen running at Cebit, and according to rumours, it should end up to be just a bit louder than the GTX 580.
Of course the 22nd of March is still more then a week away so we'll hold on to see who will prevail in the high-end market once the first benchmarks start to appear.