Hi,
I did have similar problems with long simulation times in mws while
high Q structures were considered. However I realised that significant
reduction in simulation time was achieved by carefully going through
the possible options within each solver (transient or eigenmode).
For example, for high-Q structures, as you may know, it could be faster
to simulate from DC (0 Hz) up to a desired frequency(f_upper) rather
than to simulate between two frequencies, with the lower one close to
f_upper (i.e. Fourier between time-frequency).
As a beginner then, I found valuable information relevant to the above
matter by reading the 'Advanced Topics' booklet. However, each project
requires perhaps an individual approach.
I eventually relied my phd research on MWS, with actual measurements
(DRAs) being in close proximity with MWS results (|error|<2-3%).
Interesting...