Help with planned rig

[wlefevre]

I am planning to build a custom LTC/FTC mining rig... I am going to be running an ASRock H81 Pro BTC motherboard, 4 GB Corsair RAM, Pentium Dual-Core Processor... I will be starting out with 1 Sapphire Radeon Toxic R9 280X and will buy 2 more for a total of 3 after a few months. What size PSU should I use?

Thanks in advance for any help.

 

[i7Baby]

1200W eg Corsair AX1200

 

[wlefevre]

1200W eg Corsair AX1200

Thanks so much. Which would be better, a Corsair or a Thermaltake?

 

[i7Baby]

See http://www.tomshardware.com/forum/id-1804779/power-supply-unit-tier-list.html - Corsair AX (tier 1)