I don't really have any experience with laptops, but give this a try to see if it helps at all:
1. Open up your Nvidia Control Panel
2. Click "Desktop" on the top drop-down menus
3. Click "Add Desktop Context Menu"
4. When you open Battlefield 4, right-click and I think the option comes up to run with Nvidia card
I am having a similar issue. Played the game for about 4 hours yesterday no problem on ultra. All of a sudden every time i try to join a match it lags like its using the dedicated card instead of Nvidia. The loading screens start loading ok but as it loads it slows down to a crawl. The issue is happening on BF4 and BFHL. I am able to run other games like Rainbow Six Seige on ultra. These are the only games with the issue. I have tried everything I can think of. Setting the game to run on Nvidia. Disabling Orgin in game. Running as Admin. Disabling the Intel card. Reinstalled origin and the Nvidia drivers. I also repaired the the game and everything came back fine. Any ideas? Thanks.
System:
Alienware 17R2
Windows 10
Intel(R) Core(TM) i7-4720HQ CPU @ 2.60GHz, 2601 Mhz, 4 Core(s), 8 Logical Processor(s)
Intel HD 4600
Nvidia GTX 970m
8gb Ram
P.S If this is the wrong place to post i apologize, please let me know. I figured it fit in the same ballpark as the person above me.
It appears I've now got the same problem.
Using the NVIDIA Control Panel used to work for changing which GPU was used, but now it doesn't (Only for Battlefield).
