RAM usage, GPH and other questions

[dbuddy]

I got a few questions and feedback:

Actually running a I7 3770k, 24 GB Ram, 3 GB GPU.
I can only run 15 or 16 instances flawless with highest Gold per Hour.
With 20 instances i reach 23 or 24 GB Ram sooner or later which leads to a huge gold per hour drop (some of the bots decrease by 50% gold per hour)
i splitted my 20 instances to 10, 5 and 5

I also have bugs sometimes that login isn’t possible for 1 account (maybe due to high load) If i restart it works.

Yesterday i suddenly had a really high death per Hour counter while i was away. Network problems? Anything else that can cause this?

And sometimes i got a strange bug that i cannot create a game (button is grey) – maybe some kind of „tagged“ feature from blizzard?

Are there steps i can do to reduce RAM usage?

RAM is actually a bit expensive, i don't want to upgrade from 24 to 32 gb only to see that GpH is high again for 2 more bots.
can add a log soon