jaystep :
ok thanks for the reply so will it still work considering those circumstances that i only have 470 watt? or should i pass on getting it
Dell uses pretty good quality PSUs in their builds. If your 470W has 2 x 6-pin connectors for the GTX 560 Ti, it will probably be OK. But if the PSU only has one 6-pin, it probably doesn't have the +12V specs to handle the card at full load. Look on the PSU's nameplate. Find the specs for the +12V rail(s). List them, and list the wattage for those rails. Or post a pic of the nameplate here.
Btw, unless you are getting a really good price on that old card, you can find the new GTX 1050 for ~$110, it and is a 75W card compared to the 560 Ti (170W). It is faster too: http://www.hwcompare.com/33023/geforce-gtx-1050-vs-geforce-gtx-560-ti/