Indesign extreme lag and freezing

[margheritab74763182]

Hello there. 
I'm using Indesign on a brand new machine (two days old dell xps, 16 gb ram) and i get constant and really annoying lags and freezing everytime i open two documents at once, which makes it impossible to work since I need to work with multiple documents at a time with many cross-references. When I close the second document it often goes back to normal, or at worse when i close and re-open indesign.

This way though, it's impossible for me to keep up with my work.
Any suggestion?

[Geоrge]

Is auto-preflight off?

[margheritab74763182]

it wasn't. Turned it off now, but no changes at all.

[Geоrge]

Ok, do from both files idml, open it and save as new indd, open new indd files and check it. If not helps send your example files to support, let they check it why you have so slow work if both files opened at once. 

[margheritab74763182]

Done with no success.The thing is, it doesn't happen with only two specific files, but with every file. I just need to open a second document while working on another one, and suddenly i get the freezes and the lags. So I don't think is a problem of file corruption or something similar. 
Tried to reset preferences as well.

EDIT: I also tried to open, instead of a heavy file + medium file, 1 medium file + 2 small files. This way it seems to be working fine.

Could it be a problem of allocated resources? Like indesign can't handle them.
The thing is I always used indesign this way, even with older machines, and I had no problems at all, I even worked with 700+ pages books made by 5-6 heavy files, and it worked like a dream.