I've had a couple of WTF moments from SS20s.  Best one was when I got a
retired SS20 that I cracked open to find one SM71 MBus CPU and one Dual Ross
100 MBus CPU.  It had been in reliable production, as a 3 proc box, for a
couple of years with one 70MHz, 1MB cache CPU and 2 100MHz, 256KB cache
CPUs.  Solaris reports that it's using all 3.  That's some robust
architecture.