I'm wondering if i need to upgrade my 460 psu . I have a xps 8300 with raedon hd 6770 installed and was thinking about getting the nvidia 560 ti. I read that this psu is capable of more then 460 but will it be enough for that new card.. Also would it be a good idea to switch cases i own a extremeengine 3t which i guess has much better cooling system and it is standard size???
No upgrade needed, I use a GTX260 (mild OC) with an HP 460 watt PSU. No problem. The gtx260 draws about 10 watts more than a 560ti before overclock. (The 560ti draws about 60 more than the 6770, but you are still not pushing a 460 watt psu).
If you want to cross check, do the math. Your CPU has a rated max TDP, google it and find it. I'll assume 125 watts TDP. Add 50 watts for MB, memory and slop. that leaves you 250+ watts of +12v for video card. The 6670 used 108 watts. The 560ti uses about 170. Definitely more than the 6770, but barely pushing the 460 watt psu into it's efficient range.
EDIT: If you are a huge overclocker than forget what I said. The 560ti overclocked and overvolted can use up to 100 watts more than stock, roughly 270 watts, which puts you at the edge of what that 460 can deliver. A mild overclock would only add another 15 watts or so. Here is a reference. http://www.hardocp.com/article/2011/02/01/galaxy_geforc... Note in the ref that they are measuring at the power cord, so a mild OC 433 watt load (assuming 80% efficiency) is only 433*0.8 = 346 watts of load against the 460 watt PSU's roughly 400 watt +12v. Note the non-OC 560ti used 418 at the wall or roughly 418 *0.8 = 335 watts. Note2: The base system for this measurement is Core i7 920 overclocked to 3.6GHz which will draw another 50 or so watts above rated TDP on the processor. Thus you have another 50 watts to play with compared to the article unless you are OC'ing your processor.