What ever happened to Tandem and NonStop OS 2093
I understand what you are saying, at least in terms of it not mattering for writing correct code.
However, often the details of instruction end matter quite a lot.
The same is true of other "black boxes", like memory and disk access.
Of course. I think one become a bit god when one can figure out when to bother with the finer details and when to ignore them. I never could and this is one reason...
If you don't know how they work, it can sometimes be impossible to properly optimize your code.
If you mean as an application programmer, sure, if you are only talking about SMP systems. Other forms of multprocessing require quite a bit more knowledge to make good use of. Transparent multiprocessing is one of the holy grails of computing.
Certainly an OS programmer will need to know the effects of at least a small subset of the ISA executing on one CPU and its effect on the others and the system as a whole.
No SMP system is perfect, and there is always someone that will have to learn about the tradeoffs and account for them.
Aside: You might like to read about SGI's Origin systems.
They can be viewed as a big SMP box, or as a network cluster, or as a ccNUMA machine, depending on your application.
Well, most of the time it isn't program counters you need to worry about, but how memory is accessed. Cache coherency is still one of the biggest problems to solve on an SMP system. Some implementations are very naive and simple, and don't deliver optimum performance.
However, even PeeCee SMP is pretty much transparent to the application programmer.
That sounds like broken SMP.
Sure I could. "Little" was vague, but not as vague as, say, "Some". And "The rest" is completely accurate, to infinite precision; you...
I can't parse that.
I see that kind of flexibility as a different and more complex problem than CPU dependencies in SMP.
No one wants to pay for it these days, except at the high end, and often not even there. They rather pay for more speed.
-- shannon "AT" widomaker.com -- "That which is overdesigned, too highly specific, anticipates outcome; the anticipation of outcome garantees, if not failure, the absence of grace." -- William Gibson, All Tomorrow's Parties
What ever happened to Tandem and NonStop OS 2094
Alt Folklore Computers from Newsgroups