Run gta with lower graphic card

1. On the install folder of your GTA IV
2.  Create a txt file named commandline.txt
3. Copy thye following  blue code

-DX9/high
-noprecache
-nomemrestrict
-novblank
-fullscreen
-availablevidmem 2.500
-percentagevidmem 100
-stereo
-framelimit 0
-noswapdelay
-forcer2vb
-monspecaudio
-norestriction
-memrestrict 188743680
-memrestrict 209715200
-memrestrict 230686720

-availablevidmem 2.500 is the command that allocates the RAM memory for video memory