How to avoid slowly tyCache in BirthFlow? Which are important parameters?

[Alexx31]

Hello,

I have a big destruction scene of multiple caches, some start getting extremely slow, when reading them into a BirthFlow.
I'm struggling how to proceed with this project.

As in thread before written I have enabled "Subframe Scale down" to get the Cache properly read. 
(what exactly is that?)

- Are there rules how to keep a fast workflow? Is "time step" important when reading a birth flow? 
Does it slow down when it is anyway only cache with single frames?

Thanks for advice

[tyFlow]

If all of your imported particles are born on the first frame of the sim, you can adjust the birth range of the Birth Flow operator to be just that frame, rather than the whole timeline. That will prevent it from reading and processing all cached particles every frame.

[Alexx31]

In my case 99% were born on the first frame and only 1 % is born later.
I guess so I have to keep it on reading.

Maybe I should assign particles an own particle group.
I‘m just running out of export group letters, I could easily use 100…

I remember I can’t use sim group letters, if they should still interact.
Or is there a setting to let always all sim grouos interact with each other?
Then I could lend me those letters to double the amoubt of available letters.