If simulations could be parallelized, why didn’t they invest in parallelism 20 years ago?
It was unecessary, because the fast easy path (faster serial speed) was still paying fruit.
(by “parallelism” I mean making their simulations parallel, running on clusters of computers) What does “unnecessary” mean? If physical simulations were the bottleneck and they could be made faster than by parallelism, why didn’t they do it 20 years ago? They aren’t any easier to make parallel today than then. The obvious interpretation of “unnecessary” it was not necessary to use parallel simulations to keep up with Moore’s law, but that it was an option. If it was an option that would have helped then as it helps now, would it have allowed going beyond Moore’s law? You seem to be endorsing the self-fulfilling prophecy explanation of Moore’s law, which implies no bottleneck.
(by “parallelism” I mean making their simulations parallel, running on clusters of computers)
Ahhh, usually the term is distributed when referring to pure software parallelization. I know little off hand about the history of simulation and verification software, but I’d guess that there was at least a modest investment in distributed simulation even a while ago.
The consideration is cost. Spending your IT budget on one big distributed computer is often wasteful compared to each employee having their own workstation.
They sped up their simulations the right amount to minimize schedule risk (staying on moore’s law), while minimizing cost. Spending a huge amount of money to buy a bunch of computers and complex distributed simulation software just to speed up a partial bottleneck is just not worthwhile. If the typical engineer spends say 30% of his time waiting on simulation software, that limits what you should spend in order to reduce that time.
And of course the big consideration is that in a year or two moore’s law will allow you purchase new IT equipment that is twice as fast. Eventually you have to do that to keep up.
(by “parallelism” I mean making their simulations parallel, running on clusters of computers)
What does “unnecessary” mean?
If physical simulations were the bottleneck and they could be made faster than by parallelism, why didn’t they do it 20 years ago? They aren’t any easier to make parallel today than then. The obvious interpretation of “unnecessary” it was not necessary to use parallel simulations to keep up with Moore’s law, but that it was an option. If it was an option that would have helped then as it helps now, would it have allowed going beyond Moore’s law? You seem to be endorsing the self-fulfilling prophecy explanation of Moore’s law, which implies no bottleneck.
Ahhh, usually the term is distributed when referring to pure software parallelization. I know little off hand about the history of simulation and verification software, but I’d guess that there was at least a modest investment in distributed simulation even a while ago.
The consideration is cost. Spending your IT budget on one big distributed computer is often wasteful compared to each employee having their own workstation.
They sped up their simulations the right amount to minimize schedule risk (staying on moore’s law), while minimizing cost. Spending a huge amount of money to buy a bunch of computers and complex distributed simulation software just to speed up a partial bottleneck is just not worthwhile. If the typical engineer spends say 30% of his time waiting on simulation software, that limits what you should spend in order to reduce that time.
And of course the big consideration is that in a year or two moore’s law will allow you purchase new IT equipment that is twice as fast. Eventually you have to do that to keep up.