This is the computer I just built for $1300 (a little over your budget, but it gives you an idea what you can do)
http://pcpartpicker.com/user/s4in7/saved/3YZQ
CPU: AMD FX-8320 3.5GHz 8-Core Processor ($152.99 @ NCIX US)
CPU Cooler: Corsair H60 74.4 CFM Liquid CPU Cooler ($79.98 @ OutletPC)
Motherboard: Asus SABERTOOTH 990FX R2.0 ATX AM3+ Motherboard ($177.69 @ Amazon)
Memory: G.Skill Ares Series 16GB (2 x 8GB) DDR3-1866 Memory ($144.00 @ Newegg)
Storage: Toshiba Q Series Pro 128GB 2.5" Solid State Disk ($93.99 @ Best Buy)
Video Card: VisionTek Radeon R9 270X 2GB Video Card (2-Way CrossFire) ($234.99 @ Dell Small Business)
Video Card: VisionTek Radeon R9 270X 2GB Video Card (2-Way CrossFire) ($234.99 @ Dell Small Business)
Case: Antec Three Hundred ATX Mid Tower Case ($64.98 @ Newegg)
Power Supply: Thermaltake Black Widow 850W 80+ Bronze Certified Semi-Modular ATX Power Supply ($139.98 @ SuperBiiz)
Total: $1323.59
(Prices include shipping, taxes, and discounts when available.)
It's more powerful than the computer woltej1 posted above, but it is $100 more.