🚀 go-pugleaf

In article <39361@lll-winken.LLNL.GOV> brooks@maddog.llnl.gov (Eugene Brooks) writes:
>In article <3893@scolex.sco.COM> seanf@sco.COM (Sean Fagan) writes:
>>most "killer micros" is defficient because I can't do *real* DMA (it tends
>>to steal cycles from the CPU).  (N.B.:  some K.M.'s *do* have *real* DMA.
>>I'm waiting for them to come out with *real* I/O subsystems [using, say, a
>>68000 as a PP].  Then they will scream, even compared to a Cyber.)

>A 68000 is probably not fast enought to handle IO for a good killer
>micro.  

A PP-type processor does not need to be fast, really.  If it's fast enough,
you turn your system into a dual-processor system, with heterogeneous
processor types (it can be done, and has been.  Mach can, I think, be made
to work rather well with it).  By having a, say, 16-MHz 68k serve as the I/O
processor for a KM (say, a 67MHz R6k), and doing the system correctly, then
the 68k still has a bit of idle time (say, 1-5%, not counting time spent
waiting for i/o to complete).  More, and you should probably retune /
redesign your system; less, and you should have a slightly faster processor.

PP's for a Cyber are *slow*.  But they get the job done real well.

>Killer Micros will soon dominate the world of computing, UNIX already does.

I don't think so.  IBM still dominates the world of computing, along with
FORTRAN and COBOL.  Personal computers are catching up, though.  Give it
another 5 or 6 years (i.e., more people use an IBM mainframe than use an PC
[except, possibly, as a terminal to the mainframe]).

>DOS users are not computing, but saying just what they are doing is not
>appropriate for public consumption.

They're using computers, aren't they?  Guess what they're doing, then:
they're computing.  A very small percentage of computer users need pure
number-crunching power (or else everyone would go out and buy a Cray or i860
8-)); a larger number of users would like to see more MIPS (for drawing
speed) and more *throughput*.  Again, as I've said before, a CDC Cyber
170/760 is slower, MIPS-wise, than quite a few of the newer RISC systems out
there.  However, it *feels* faster because of the throughput difference,
even with 100 users on it (speaking from experience).  When you have a
system that can compile a 10 000-line FORTRAN program in less than 40
seconds, *without* going through a cache, then I'll be happy with a KM.
Until then, however, the mainframes are going to win, and continue to be
bought.

-- 
Sean Eric Fagan  | "Time has little to do with infinity and jelly donuts."
seanf@sco.COM    |    -- Thomas Magnum (Tom Selleck), _Magnum, P.I._
(408) 458-1422   | Any opinions expressed are my own, not my employers'.