sorry its 7300LE , that was a typo lol , and yes you are right my motherboard doesnt support SLI its just has one 16x slot! so is there any tweak/setting i can do to increase the performance of my current card? i dont want to scrap this one as its not even been an year since i got it , i am planiing to make my RAM 4gb , will it effect gaming performance much?

Well, with that card the extra ram would do next to nothing, it would make your computer run faster while multitasking, but apart from that it would do nothing, with the 2gb i have in my pc it is never fully used, so i think that, unless you are planning to be doing DX10 gaming then 4gb is way over the tope, especially if its already playable, and if it isnt playable it would be the card holding it back anyhow,

As for improving the performance of that card you could try overclocking it, for that i would recommend to try ati tool, but dont touch anything unless you are totally sure that you know what you are doing. im not sure of the overclockabilty of that card, but i know that if you are luck you can around 30-40% increases in perfomance, i managed to do this to my card but it is known as one of the easiest to overclcok, but before you do anything i would recommend reading some begginers overclocking guides, if you dont already know how to OC safely


EDIT: as an example of how OCing affects performance: without the OC i can play C&C3 with everything at high and no AA, with a 30% OC i can play it with 4x AA