There are cards on the market today that have 4GB of GDDR5 on-board. Those are however dual GPU cards. The standard GTX580 has to settle with a 'paltry' 1.5GB. MSI have took note that the enthusiast market are now gaming at resolutions higher the 1680x1050. 1920x1080 is now the norm with 1920x1200 becoming increasingly popular. There are those who crave higher resolutions and with multiple monitor setups now being fully supported by many recent games, higher and higher amounts of Vram are required to keep pace. It's for this reason that MSI have seen fit to employ 3GB of GDDR5 to the Xtreme Edition of their GTX580. Overclocks remain untouched but the cooler has been re-designed in the guise of Twin Frozr III.