What were the fastest CP/M computers ever built?
I'll restrict this to the Z80 variant of CP/M, no CP/M-86, CP/M-68k etc.
Z80 compatibles with higher clock frequencies or more instructions/clock or other modifications count, as long as it ran CP/M using mostly the Z80 ISA. Overclocked homebrew systems count.
Multi-processor systems count (total attainable MIPS).
Emulated hardware does not count, it must be an existing Z80-compatible CPU that's somehow running on real silicon.
FPGAs etc. are worth considering if someone has actually done that for some other purpose than "it would be cool, I have this FPGA lying around here anyway, so let's just do it, it's easy". E.g. for some accelerator of a legacy system that served a real purpose.
To avoid confusion, some background on the question: When reading about CP/M machines, I found some were a lot faster than your run-of-the-mill Z80. So I wondered how far people actually pushed this, when CP/M was still in use. Therefore "must run CP/M, no emulated hardware". Then someone mentioned FPGAs, so I said "ok, if people used this to speed up real CP/M systems, then ok".
Multi-processor systems (which I didn't exclude, because that would have been an obvious way to make it faster) only make sense if they somehow ran a modified CP/M, M/PM etc. on all cores. Lots of single machines each running CP/M (like the ZMOB, where it is used to provide an environment on each machine) don't make for a faster machine in total - they are still single machines, each running its own CP/M, even if they communicate.