[zaarn]

>So maybe the total amount of computing power is equal?

Probably not. Those 18bit words likely contain 2 bit parity to prevent space radiation from making this go bad. Plus, it's only one machine, not two, the two always run in parallel (for the CSS, the FDS only has one running at a time and AACS is turned off if not needed) and redundantly in case on fails, so in total you're running about 180'000 instructions per second, not 360'000. The memory totals 34 kilobytes (18bit words in two of the memories, 16 in the third), with a simple redundancy like the computer itself (ie, each computer has it's own memory).

The CCS is also responsible for managing the memory of the other two systems (MEMLOAD), so their realistic instruction speed may be limited by slower memory access in memory heavy applications.

Even all systems combined, I don't think the voyager is faster than an Apple II within an order of magnitude.