You need to limit the number of CPU threads with genproclimit=4 or whatever number of cores you have to spare.
Then I wonder: what is this setting: minermemory=2. Gb?
But memory also matters, right? I have two Win7 computers with identical setup and similar configs:
EXACTLY Memory matters,
"the only solution if you need more memory is more memory"
Computer 1: 4 CPU cores, 16Gb memory, 3.2Gb used; mining with 2 cores
Computer 2: 6 CPU cores, 16Gb memory, 4.3Gb used; mining with 4 cores
Shame on you lol 
Computer 1 yields nearly twice as much ERC as computer 2 with only half the number of cores!
I am having the idea, that computer 2 has a higher percentage of cores running and if you stress the cores to much,
they slow down, because they lag enough power for their basic operations.
I feel just putting pc 2 on 3 cores and its ahead of pc 1
this is much more fun then waiting for pos, isn't it?

have fun
Matthias
.