Would cpu upgrade makes difference for....

[zzzxtreme]

hi, my nephews' PC is an HP6155D

Core 2 Duo E4400 (C) DC 2.0 GHz
800 MHz front side bus
Intel 945G
2GB RAM
ASUS ENGTX260 TOP 896MB

I just recently upgraded the graphic cards
running windows XP, all updated, latest dx , HDD on IDE mode despite having SATA HDD

they say playability is ok, but some games, when I move the character up to look at the sun, it lags, even at low settings. (1440*900).

what can I do to improve gaming experience with minimum spending ?

thanks in advanced

 

[shagrathdex666]

you could always try to overclock the cpu by a little margin 2.4 ,2.5 or getting a tad
faster processor they are now about 80 to 120 $

 

[enzo matrix]

which games are these in?

 

[sportsfanboy]

Also make sure that power supply can produce enough power to run the card correctly.