np, so when you are trying to import/update 100k devices. are you doing any batching (eg persisting many entities in one bang instead of one and one)?
another thing you could look at if updates is an issue is to enable entity caching, looking at what attributes that can be lazy loaded etc.
if you're using the same query over and over again query caching would also speed things up.

• as always, caching need to be done right, or it might even slow things down