> Partitioning a circuit into fast-rate and slow-rate components is not always an easy problem.
> After the partitioning, the coupling relationship between the two components needs to be
I agree with you, Baolin, it's not easy. But it's been done before, and as you say, if the coupling
is loose or can be approximated, then we can consider this a solved problem. If the coupling
cannot be approximated without compromising precision (two examples I often consider are
a) power net injected global coupling and b) fully-coupled memory word/bit lines), then this is
not solved and I consider it an area ripe for innovation.
> For most analog circuits, the question is whether one should consider Parallel Spice simulation
To paraphrase Mandy Rice-Davies, "yes, well you would say that, wouldn't you?" [Note 1]
For 30 years, parallel SPICE has been the subject of active research. I've known many of
the developers, at Silvaco, NEC, Siemens (Infineon as now is), and others, and used some
of them. None have been able to reach more than a sub-linear acceleration with the number
of processors, and so they've really not solved the problems (load vs. solve; network
latency; memory bandwidth, etc). For some the flattening off of performance gain can be
really quite remarkable.
> If one uses Parallel Spice simulation, the simulator does more computation but the
> work can be done concurrently on different CPU cores.
With the matrix all in shared memory? What about memory bandwidth? What if it is too
big a matrix to fit in memory? And multi-core is scaling pretty slowly - consider memory
bandwidth, for example. It would be interesting if the problem could be distributed more
widely, across network-connected machines, along the lines that is being worked by at
least one other company.
If you've solved these problems (and the unmentioned myriad others) - and I realise
you're not going to want to discuss them, given the early stage of your company, and
the need to maintain some sort of propriety - you've pushed forward the boundary,
and I wish you luck. I've been involved in circuit simulation from many angles for 28
years, and this will be fun to watch. I wish you well.
Note 1 : http://en.wikipedia.org/wiki/Mandy_Rice-Davies
[Not, I hasten to add, that I
am suggesting you are having an affair with a British cabinet minister and a Russian
military attache. Just to make it clear!]