(HP Pavilion G7-2251dx and probably many other AMD laps based on A-x apu's)
*This is for the A8-4500 apu but may also work for you*

(depending on you laptop you may need to download AMD´s Overdrive in my case CCC wont allow me to tweak those options)

Hey I found out how to get the best out of my laptop, do everything this guy says in the video but instead of overclocking the GPU use AMD Overdrive to UNDERCLOCK IT !
Yes it sounds crazy... but believe me: It works. Set your GPU clock to 600MHZ not 645 as default. My fps went from 26 to 50 no joke. Also you may deactivate turbo core, im not completly sure but as far as I tested it , while it boosted my frame rates for a while(up to 60 with my config) it made my fps less stable and overheated my cpu to the point of Thermothrottling which resulted in even less fps.

To avoid Thermothrottling and use Turbo Core you need to clean up your fan, replace thermal compound (use silver paste) and mod your lap by adding another fan or improving airflow in other ways.. do some googling. Mine was not designed for Turbo core actually.. the cooling is not enough.

THE EXPLANATION behind this is that APU's like amd A8 steal processing power from the CPU to feed the GPU ... give too much to the GPU and CPU goes way down on frequency to the point were your FPS drops. Give too little to your GPU and your Fps drops as usual. So for me 600mhz was that perfect equilibrium, yours may be different, depending on your model or many other factors.

Make sure PowerPlay on Catalyst Control Center is locked on Performance, search the program in the search bar. Also to leave this settings permanent you can configure Overdrive under the tab Preferences to load them on every boot up!

NOTE: I tested this using War Thunder set to Low graphics.

My specs are:
Hp Pavillion G7-2251dx 17,3''
-6gb ddr3 Ram
-A8-4500 apu
-Seagate Hybrid 500gb/8gb
-Some extra holes and tape-improved airflow on laptop (extra fan coming soon)

PD: you may want to upgrade your processor: check compatibility, I can upgrade to A10-5750M.