Brilliant post, clearly stated well thought out! I'm also having this issue and only managed to alleviate the problem with work-arounds I'd like to see DICE confront the issue directly though.
Fix attempts:
1: Change process priority of bf4.exe to low in taskmanager
2: Editing settings in user.fg:
3: Turn off hyperthreading in BIOS
4: Update punkbuster manually
5: Turned off v-sync which managed to remove the sudden drops with gradual drops that are less distracting and some (minimal) screen-tearing
(This goes without saying but I've turned all the graphics settings to low with no avail)
Specs:
i7 2600
Radeon HD 6800
8GB RAM
Windows 7 64 Bit
Catalyst version 13.11 (Oct 28th Driver)
EDIT: thought it was worth noting this issue occurs for me in singleplayer as well.
