🚀 go-pugleaf

First off make sure you are comparing apples and apples.  DEC has produced and market four revisions of the 70832 family chipset if I have been keeping count
properly.  There may be a couple more I missed and I know that there are more
in developement.  

Second the rtVAX has a slight braindamage, one level of page table translation
is bypassed.  This provides either (1) cheaper simpler hardware or (2) 
the ability to use regular vax chips with defects in this area.  It also
prevents you from running a standard Digital full function operating 
system (VMS, Ultrix, BSD UNIX) on it.  YOu could probably do a real
UNIX port for one but no one has.  [after all its about the same level of
page system support as a 386 chip]

THus its selling into a wider market without impact on their captive 
integrated systems market.  [See the recent discussions on comp.arch about the 
$50,000 card cage most vendors sell you when you buy midrange systems. Or the
DEC pricing on the CI star coupler, a completely inert electrical bus that
costs a small fortune to buy and maintain.]