An example of MIMD system is Intel Xeon Phi, descended from Larrabee microarchitecture.
https://en.wikipedia.org/wiki/Larrabee_(microarchitecture)
Its x86 cores were based on the much simpler P54C Pentium
https://en.wikipedia.org/wiki/Xeon_Phi
That is the core from the generation before the Pentium Pro. Larrabee was supposed to be a GPU, wasn't good enough to compete at that, then they rebranded it as Xeon Phi but cancelled it a few years ago.