Graphics :/

Hi guys , im begginer in gmod.
So , we yesterday with my friend wanted to make a fort.
So we did make it. Later i noticed an lagg & some stupid figures blinking all time :c

http://bildites.lv/images/8co43iype3aqj51eoyb8.jpg

btw , on my old pc wasnt that sh!t :confused:
It’s annoy thing >.>
Thanks…