XPS non support

       i bought this xps720, no screen on ebay for a grand it was a year old and i have it for 4 months and it runs ok. when i look at new processor, intel new i7 cpu. i have a look at motherboard inside case and find it not atx and it have very weered power plugs 1 x standard 24 pin and a reel strange 20 pin plug i never see befor. it cleer that atx will not fit case so i then ring dell suport to find out cpus can be instaled as i think upgrade cpu, memory and card, card not reel good very low power 8800 gtx !

       the cute chinese babe at support say the dell xps720, not suport the fontside bus 1333 proper and only cpus to 2core 6850 or to qx6850 can be instaled in dell xps720 and not listen to forum as many bad people tell dell customer to do wrong thing and dell suport have many people ring to complain that the e8500 not work and e9450 not work so she tell me not to swap cpu dell will not suport!!!!!

        anyone know weer the information page for the cpu the memory is? post link can finf no information on dell site   so ask on forum.

         any dell people heer kjnow anything? which cpu upgrade to?

the xfx motherboard company post this information why not delll http://www.xfxforce.com/en-us/products/motherboards/6series/~/ecms.aspx/XFXCPUCompatibilityList-Intel.pdf