Welcome to ROG potatopigs
🙂Laptops Graphics Card will never work with the same speed as the graphics card on the PC. They will be always weaker.
The same situation is with CPU. Did you installed latest Drivers for your GPU. By the way is your laptop connected to the charger when you play BF4 or is working on battery?. In most cases FPS drop will be noticeable when playing on the battery. But I can be wrong in these cases so maybe wait for answer someone more experienced than me.
Case: Corsair Obsidian 900D Cpu: Intel Core i7-3970X Extreme Edition Cpu Cooling: Swiftech H320
Mobo: Asus Rampage IV Black Edition Mem: Kingston 32GB HyperX Beast 2400MHz
Gpu: 2x EVGA GeForce GTX 780 Ti Superclocked w/EVGA ACX Cooler Psu: Corsair AX1200i
Ssd/Hdd: 1x Samsung 840 Evo 250 GB / 1x Samsung 840 Evo 500 GB / 1x WD Black 3TB
Monitor: Benq 24" XL2411T