Do not purchase that system, whatever you do. You have listed a system with a last generation CPU, an unnecessary cooler, an over abundance of memory, a faulty PSU, and a run of the mill case. You could get a much better system if you purchase something like this:
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-6500 3.2GHz Quad-Core Processor ($204.99 @ Newegg)
Motherboard: Gigabyte GA-B150M-DS3H Micro ATX LGA1151 Motherboard ($56.98 @ Newegg)
Memory: Kingston HyperX Fury Black 8GB (2 x 4GB) DDR4-2133 Memory ($31.99 @ Newegg)
Storage: Western Digital Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive ($47.49 @ OutletPC)
Video Card: Sapphire Radeon RX 480 4GB Video Card ($220.00)
Case: Corsair Carbide Series 88R MicroATX Mid Tower Case ($47.99 @ Micro Center)
Power Supply: Antec TruePower Classic 750W 80+ Gold Certified ATX Power Supply ($59.99 @ Newegg)
Total: $661.43
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-06-29 18:45 EDT-0400'
Overall a much better system, and one which will last you. If you already own that system, I would advise returning it. If that is impossible for you to do, then the best recommendation I can advise is to
change the power supply. The Corsair CSM series is faulty, with a high failure rate, and consists of cheap components. Currently the best power supply deal I have seen is the one I have listed above, the Antec True Power Classic. At a price point of $60, it is rated as a tier 2 unit (by the PSU tier list), with great efficiency, as well as top notch components.
The case listed is the Corsair 88R, which I find is great for its current price.
All in all, either purchase the system I have listed, or make the necessary upgrades before purchasing an RX480.