go on www.tomshardware.com
they do all sorts of video card testing...find those 3 vid cards and see for yourself....
u'll find those benchmarking testing quite useful...how does it perform better you ask??...i have no idea...all i know is that they just do...take a look at the benchmarks yourself...
as for the power supply line for pci-e...the 3870 requires...i used to own a 3870 myself a while back....but no idea about the 3850...
i would invest in a PSU anyways...it's only $30-50 anyways...the last thing you want to worry about when ur upgrading is needing another updgrade because there's not enough power..
but anyways...looks like you have time...just keep shopping around for now...but go to that site i gave link to...take a look at all the benchmarks...and compare the performance on the site...then go on newegg and compare prices....see which one really is worth it for you....
