the R9 290 will peak at 300W Unless you get the vapor X, those things peak at damn near 400W.
So 300W for the GFX Card, your CPU is in the 280W area when overclocked to 4.0Ghz area 1HDD = 5 to 10W 2 sticks of ram 6W every fan 3W and the mobo does 20 to 50W So Right around the 650 mark. There's even some guys on forums who pulled off running a 290 with a 550W PSU. You'll be cutting it close with the 650 but it will do in the long run