Megahertzes mean nothing in this context. A specialized DSP/FPGA found in a midrange DSLR can easily outperform even a multi-gigahertz multi-core desktop processor at specific tasks. There was actually some talk about this at the summit - it was told the current time required to capture an image is a balance - if you would wait 10 minutes for an image, you would a lot better looking images. If you want quicker capture, quality will suffer.