Dramatic FPS Drop

Hey Steam players~

Does anyone—who is very PC savvy—know why my FPS dramatically drops from 80~100 to 10~20?

I noticed this as I was playing Elder Scrolls Online: whenever I logged in and spawned in the world, my FPS counter at the bottom left corner tells me I have 80~100 FPS for a few seconds then drastically drops to 40~60, then drops again and stays at a constant of 10~20. This tells me my laptop is capable of running games around 60~100 FPS. I tried some BIOS settings (most of which seems confusing to me, so some BIOS pointers would really help me out) and I'm not sure what settings to change if I decide to overclock with AMD OverDrive and MSI Afterburner.

I'm not entirely sure of what to do to keep my FPS at least around 40~60 or 60~100 and why my FPS is being bogged down.

Here are my specs:

Name: HP Pavilion 17-e123cl (laptop)
Display Driver/Graphics Card: AMD Radeon HD 8550G (not sure if integrated, discrete, or dedicated)
Processor: AMD A8-5550M w/ Radeon (tm) HD Graphics (2.10 GHz)
RAM: 8.00 GB
System Type: 64-bit OS and processor
Hard Drive: 1TB
BIOS: InsydeH20

Default CPU Core Speed: 2100 MHz
Default GPU Clock: 720 Mhz
Default Memory Clock: 800 Mhz
GPU Temperature: ~36° C (AMD OverDrive readings, idle)
CPU Temperature: ~18° C (AMD OverDrive readings, idle)

I know it is not recommended to overclock a laptop but I am willing to take the risks. :)
(Sorry if I posted this in the wrong section!)

Dramatic FPS Drop