I have a computer which should really be able to run GTA IV highest settings with no lag but it plays around 25-40 fps on medium settings. Processor: AMD FX(tm)-4100 Quad-Core Processor (4 CPUs), ~3.6GHz Memory: 8192MB RAM and my video card is a AMD Radeon HD 7700 Series. Surely this should run GTA IV with good fps right? Also I have lag issues with Assassin's creed III.