Tyler7 :
CTurbo :
By which company? 500w is enough power, but there are no good 500w psus on the market. It's important to get a decently reliable psu.
( sorry im a bit lost here) The thing is i have a gtx 960 and the vgtx 1070 only uses 30 more watts so surely it will be fine if i have enough power?
again it has not so much to do with power as with quality.
when you buy a car, you don't go to the car dealer and say "give me a car that can reach 150 miles per hour" and just buy the next best thing that has a tachometer that shows "150".
PSUs are the same. just because the PSU says it's 500W doesn't mean it can deliver it when you need it to, doesn't mean it can do so for many years, doesn't mean it can do so without burning your house down (worst case^^)
generally you'll probably be alright for a time. but it would be a shame if it's a low grade unit AKA a ticking time bomb and goes the way of the dodo when powering up the new system -- alongside your 1070