PSU enough for build? I can't find anything w/ current components to check

ASUS recommends at least a 750W PSU for the R9 280x, however pcpartpicker says I only need 438 watts? I've already bought all of these components, including the PSU, just waiting on shipping. Will this all work together? Is this PSU enough? Side note, I spent $1091.

[PCPartPicker part list](http://pcpartpicker.com/p/29V0D) / [Price breakdown by merchant](http://pcpartpicker.com/p/29V0D/by_merchant/) / [Benchmarks](http://pcpartpicker.com/p/29V0D/benchmarks/)

Type|Item|Price
:----|:----|:----
**CPU** | [Intel Core i7-4770K 3.5GHz Quad-Core Processor](http://pcpartpicker.com/part/intel-cpu-bx80646i74770k) | $289.99 @ Newegg
**Motherboard** | [Gigabyte GA-Z87X-UD5H ATX LGA1150 Motherboard](http://pcpartpicker.com/part/gigabyte-motherboard-gaz87xud5h) | $169.99 @ Newegg
**Memory** | [G.Skill Ripjaws X Series 8GB (2 x 4GB) DDR3-1600 Memory](http://pcpartpicker.com/part/gskill-memory-f312800cl8d8gbxm) | $79.98 @ OutletPC
**Storage** | [Seagate 600 Series 240GB 2.5" Solid State Disk](http://pcpartpicker.com/part/seagate-internal-hard-drive-st240hm000) | $129.99 @ TigerDirect
**Storage** | [Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive](http://pcpartpicker.com/part/seagate-internal-hard-drive-st1000dm003) | $61.04 @ Amazon
**Video Card** | [Asus Radeon R9 280X 3GB Video Card](http://pcpartpicker.com/part/asus-video-card-r9280xdc2t3gd5) | $316.13 @ Newegg
**Case** | [Lian-Li PC-7FNWX ATX Mid Tower Case](http://pcpartpicker.com/part/lian-li-case-pc7fnwx) | $159.99 @ Mwave
**Power Supply** | [SeaSonic 660W 80+ Platinum Certified Fully-Modular ATX Power Supply](http://pcpartpicker.com/part/seasonic-power-supply-ss660xp2) | $136.98 @ Newegg
**Optical Drive** | [Samsung SH-224DB/RSBS DVD/CD Writer](http://pcpartpicker.com/part/samsung-optical-drive-sh224dbrsbs) | $24.98 @ OutletPC
**Operating System** | [Microsoft Windows 8.1 - OEM (64-bit)](http://pcpartpicker.com/part/microsoft-os-wn700615) | $98.98 @ OutletPC
| | **Total**
| Prices include shipping, taxes, and discounts when available. | $1468.05
| Generated by PCPartPicker 2013-11-28 12:40 EST-0500 |