Just an fyi on that power supply of your's,It's something I would look at upgrading in the near future.
Min requirements for that GPU are:
750W (or greater) power supply with 1x 8-pin and 1x 6-pin PCI Express power connectors recommended
600 Watt or greater power supply1 with one 150W 8-pin PCI Express power connector and one 75W 6-pin PCI Express power connector
Guru 3D review of MSI card:
AMD R9-290X - On your average system the card requires you to have a 550~600 Watt power supply unit.
AMD Phenom II 1100t @4.0Ghz /Asus sabertooth 990fx/2x Gigabyte 3G 7950's in crossfire/500G samsung 840 ssd/16G G-Skill Ripjaw 1600/2-samsung 24" monitors 1920X1200/Corsair AX1200W psu/W7 pro 64,G19 keyboard,Roccat kone pure mouse,Cooler master HAF932,Corsair H100i water cooler,Zalman ram cooler.Sound Blaster X-Fi Titanium Fatal1ty Champion Series,Logitech Z5500 speakers,Roccat Kave 5.1 headset.