Hi, I am thinking of running my XFX 8800 GTS 640 MB in SLI mode. This is the card that I have. http://www.xfxforce.com/web/product...rce™+8800&productConfigurationId=921085 Do you think the performance of the cards would be worth paying for? Because I have one of it, I am thinking of buying another one just for this. If any of you have done it Please tell me, or some advice would be nice. Thanks.