PSU big enough?

For those of you that want the build list:

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i7-4790K 4.0GHz Quad-Core Processor ($334.99 @ NCIX US)
CPU Cooler: Corsair H100i GTX 70.7 CFM Liquid CPU Cooler ($109.99 @ Amazon)
Thermal Compound: Arctic Silver 5 High-Density Polysynthetic Silver 3.5g Thermal Paste ($6.49 @ Newegg)
Thermal Compound: Arctic Silver 5 High-Density Polysynthetic Silver 3.5g Thermal Paste ($6.49 @ Newegg)
Motherboard: Gigabyte GA-Z97X-GAMING 7 ATX LGA1150 Motherboard ($152.98 @ Newegg)
Memory: Corsair Vengeance Pro 16GB (2 x 8GB) DDR3-1866 Memory ($84.99 @ Newegg)
Storage: Samsung 850 EVO-Series 1TB 2.5" Solid State Drive ($347.99 @ Amazon)
Storage: Western Digital BLACK SERIES 1TB 3.5" 7200RPM Internal Hard Drive ($69.99 @ Newegg)
Video Card: EVGA GeForce GTX 980 Ti 6GB Classified ACX 2.0+ Video Card ($649.99 @ Newegg)
Case: Fractal Design Define R5 w/Window (Black) ATX Mid Tower Case ($119.99 @ NCIX US)
Power Supply: EVGA SuperNOVA P2 850W 80+ Platinum Certified Fully-Modular ATX Power Supply ($149.99 @ Amazon)
Optical Drive: Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer ($20.95 @ Amazon)
Operating System: Microsoft Windows 8.1 OEM (64-bit) ($99.99 @ NCIX US)
Case Fan: Fractal Design FD-FAN-SSR2-140 66.0 CFM 140mm Fan ($14.99 @ Amazon)
Case Fan: Fractal Design FD-FAN-SSR2-140 66.0 CFM 140mm Fan ($14.99 @ Amazon)
Case Fan: Fractal Design FD-FAN-SSR2-140 66.0 CFM 140mm Fan ($14.99 @ Amazon)
Case Fan: Fractal Design FD-FAN-SSR2-140 66.0 CFM 140mm Fan ($14.99 @ Amazon)
Monitor: Asus VN247H-P 23.6" Monitor ($169.99 @ Amazon)
Monitor: Asus VN247H-P 23.6" Monitor ($169.99 @ Amazon)
Monitor: Asus VN247H-P 23.6" Monitor ($169.99 @ Amazon)
Keyboard: Razer BlackWidow Chroma Wired Gaming Keyboard ($149.99 @ Amazon)
Mouse: Razer DeathAdder Chroma Wired Optical Mouse ($58.65 @ Amazon)
Headphones: Logitech G930 7.1 Channel Headset ($69.99 @ Amazon)
Other: USB Hub ($19.99)
Other: Power Brick ($17.98)
Other: Monitor Stand ($107.95)
Other: Display to Hdmi ($11.99)
Other: Display to Hdmi ($11.99)
Other: Display to Hdmi ($11.99)
Total: $3185.27
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-12-06 23:11 EST-0500

Wow that is a build there. The PSU is plenty for that build. You could even go with a good 650-750w PSU, if your not OC'ing the CPU/GPU to extreme levels. Even a quality 80 PLUS Gold PSU will do for less $, but that is up to you.