fps dropped

[toqchista]

hi;

i have i5 2400 and gtx 650;
1 month during im playing gta 5 1920x1080 resolution with mods and video card memory was orange, so it wasn't fill up whole;

yesterday i added few mcqueen cars different colors and i save they each of other in my saves; but yesterday as i remember i had't lag and fps dropped;
today im played gta 5 and i observe some moments my fps dropping from 60fps to 10-15fps and when im saying statistic at the time video card usage dropping 0%; and then also increasing 99% usage; im interested and then im open graphic setting and im got my gpu memory to be red, so game usage memory to be more than have my video card;

so maybe reason to be new mod cars?

[toqchista]

no it isn't mod reason' ;

i take out mods file and still i have lag;
i tried play 720 resolution gta 5 but still fps dropping moments; (((