Re: Ahhhh the famous intel 8087
Almost none used by ordinary mortals on DOS. You practically had to write a floating point application using a compatible compiler.
Also even later DSP and games cunningly used fix point arithmetic mapped to Integer because integer math on the CPU was faster than FP on the FPU on a 486.
However even if not wanting FP, the AMD definition of a core on bulldozer does sound a bit like part of a cpu, whereas traditionally licencing and users might have regarded a 4 core chip as being approximately like the old server MoBo with four CPU sockets. Never mind a board of Transputers each with its own everything inc DRAM and four communication links. A wonderful design considering that Intel was on 386 cpus then.
1986 - 1987 has maybe the peak?
https://en.wikipedia.org/wiki/Transputer
The 80386DX came out late 1985 (with a bug) and mainstream but very expensive 1986-1990, the 486 came out in 1989, but not widespread till 1990-1991.
I don't remember MoBos with multiple 386, but such for 4 off 486DX existed. My only multiple CPU system had two Pentium Pro. The chip that Win95/98 killed because no real swap to 8086 mode, basically a 32bit only CPU. The NT4.0 used NTVDM and WoW, so ran 16 bit code on Pro MUCH better than Win9x could. Also Win9x itself had some 16 bit code. Not a true 32 bit OS like NT.
https://en.wikipedia.org/wiki/Intel_80386
Sadly most 286 and 386 computers only ran 8/16 bit software in 8086 mode, the original 8088/8086 and choice of it by IBM held back most PC based computing for nearly 10 years with its evil almost 8080 8 bit architecture and segment registers for more than 64 bit addressing. Made it easy to port CP/M and CP/M applications to CP/M 86 and the cloned MSDOS.
MS did offer Xenix on 286 and later 386, though not much interest in that outside servers and education.