[bravo22]

The problem is a lot of the models you use are black box characterized models and not differential equations. I don't mean Julia won't speed things up a lot and won't be helpful but your point about modern sim tools using old techniques is not true. Simulation RCL in semiconductors is a huge business where customers have been paying a lot for faster solutions.

[oxinabox]

fair enough. I can't say i've seen inside how things things are made. Julia definately has cutting edge for DEs. I doublt LTSpice does, but ORCAD etc might.