I don't think Canon have ever revealed the technical specs of their DIGIC processors. Typically they just say it's "X times faster" than the previous one! I know the Digic 5+ was 17x faster than the Digic 4, but I've not seen any numbers quoted for the 5+ to the 6.
It's not just the processor clock speed, it's also the design of the dedicated GPU (graphics processor unit) that contributes to the overall speed of the camera. Since power consumption is a big factor in camera design, state of the art ultra fast processors probably aren't used since power consumption goes up with speed. There's probably some tradeoff of power vs. speed.
As for memory, I don't know how much they have in the camera. Again it's something that Canon don't talk about. I'd guess that details of the Digic processor would be something that Canon don't want other companies to learn from.
I think it is known that the Digic is an ARM (Advanced RISC Machines) device (see
http://en.wikipedia.org/wiki/ARM_architecture)