I have a alienware x51 with a intel i5 processor , 16 gigs of ram , a dell 21.5 hd monitor , a nvidea gtx oem 660 1.5 gig video card and a 330 watt power adapter . My question is can I obtain a bigger power adapter , and what is the limit as far as video cards for this computer . Also , what is the best i7 processor I could use for gaming , viewing hd movies and multitasking . My e-mail is email@example.com and my name is Ken Carroll . My son loves gaming and I use the computer for general use .