Looks like a significant increase over the K20X not just in a RAM perspective but also from boost clock and overall teraflops. I wonder when the consumer version with be available, I think 12GB of RAM would be good for some 4K Gaming!
http://www.pcmag.com/article2/0,2817,2427258,00.asp
http://www.theregister.co.uk/2013/11/18/nvidia_amd_12gb_gpu_accelerator_hpc/
http://www.pcmag.com/article2/0,2817,2427258,00.asp
http://www.theregister.co.uk/2013/11/18/nvidia_amd_12gb_gpu_accelerator_hpc/