I agree, it doesn't matter - the 1DX is a very good camera regardless of how many CPUs it posesses. I haven't had mine for very long, but it clearly beats the 7D when it comes to focusing in low light. I intended to try it out in depth during a sports event I visited the last few weeks, but unfortunately got an eye injury, so I only took a few images with it. Then my fiance took some, but she doesn't really know how it works, so that doesn't say much. There are a few in this album, but that doesn't say much, since there are many other images from the 1DX on the internet now.
But anyway, two Digic 5+ for image processing, memory card interface, rear LCD interface, live view AF and video processing. That's two.
Then we have the Digic 4, which is dedicated to handling information coming from the 100000 pixel exposure metering system. That's one more.
Add to that yet another dedicated processor to do AF computing, especially to handle the work required to measure and react to what happens between images when using Servo AF. That's another one.
On top of that, the 1DX probably has yet another processor (because that has been the architecture of the latest reincarnations of the 1D-series) to handle the normal sequence control in the camera, sensing buttons, releasing the shutter, moving the mirror and such stuff. Then we have one more processor here.
So adding these together gives five. But I haven't seen too detailed information from Canon about this, so I'm not 100% sure. Some cameras have had a dedicated communication handler for the camera/lens interface, and this camera has a processing-intense Gigabit Ethernet interface as well. Whether there's something controlling these parts that resembles a CPU (something that executes instructions from a memory is my definition here), I don't know. Could be just dedicated circuitry which just implements state machines, for example. You can do a lot with an FPGA today.