My computer quality or game?

Hello tanki!. 

i have problem with my conputer

everytime i enter games in big/medium maps (lost temple/scilence) 

my fps get really low to 6-14, espacially when i turn arruond with my tank and 

my computer screen Contains more players. i download tanki online 

to get better quallity but it is still doing it. i want to know if you know how to solve this problem

Thanks!