As this issue seems to have been resolved with new drivers I'll mark this thread as solved now.
I think there are (at least) two different causes. One is some driver problem with the Realtek network-adapter and the Windows Network Data Usage Monitoring Driver. The solution was offered on reddit some time ago and seems to affect not only Battlefield. Maybe that's what's hitting a few Nvidia card owners.
For example:
http://en.reddit.com/r/windows8/comments/1p83v0/windows_8_memory_leak_with_ndusys_high_memory/
The other cause has something to do with AMD graphic cards/drivers. And for that issue I haven't found any working solution yet. And I tried everything I read so far.
I gave up and just upgraded to a R9 270X, no issues now.
But I've donated my old 6950 to my friend and it's painful for me to see him have the same issues still.
When was the last time we had an official response on this? Feels like we've been pushed under the carpet and forgotten about. ☹️
