FPS lag issues

Hi,



I have a very weird problem here, let me explain:



I run a main client 64 bit which i play myself, usually along several other 32 bit clients. I recently took a 2 week break and just came back to wow.



Now the problem is:



If i run 1 64bit client and 1 32 bit client my 32 bit client is experiencing very high fps drops.

If i run 2 x 32 bit clients this problem disappears

If i run 2 x 64 bit clients this probem is not here either



my botting wow client is installed in seperate folder.



So i took following steps



i tried to log all the above from diff setup folders to make sure it has nothing to do with errors in files.



Also i have to mention no bot was attached to any of these clients during these tests.



Nothing has changed on my pc configuration and i was usually able to run 1 64 bit client along with 8 32 bit clients without experiencing any lag what so ever. (approx 2 weeks ago)



I have been googling maybe bliz changed something in recent patch but haven't found anything.



Does anyone has a clue what is going on?



Many thanks

FPS lag issues