My build has a 450W PSU. It is intended to take a GTX970.
Your complete system, less the GPU will not use more than 100W of power at full song. The GPU is very low power and can draw a theoretical maximum of 75W from ti's PCI-e slot (practically limited to around 60W) and another 75W or so from it's 6 pin power connector, a bit more from a 6+2. so it will draw less than 150W (145 according to spec). That's a total of 250W.
There are three reasons for the large numbers you see.
1. Manufacturers of GPUs know many customers have cheap and cruddy power supplies which cannot deliver the power that they claim. By asking for a 500W supply for their card, they ensure at least the 200W or so they need and without causing the PSU to explode any faster than usual
2. Many people on board are happy to spend OPM by suggesting big and interesting PSUs to support future (but never-going-to-happen) upgrades.
3. Many people on board don't know how to calculate the requirements and figure bigger is better.
The AMD build you posted has a 125W CPU vs the 85W of the i5 and a 250W Gigabyte 290 WINDFORCE vs 145 for the GTX 970.
It is best to keep the system load to 70% or less of what the PSU will do for long life and good health. That's about 365W for a 520W PSU. For the other system, the total power, at full song may be in the 400W range, so 70% of 600W is 420W.
The second build needs another $150 or so for the monitor, keyboard and WiFi.
We could happily increase the PSU a little and drop to a cheaper and somewhat less powerful GPU to save money.
This is the current complete system, including DVD.
PCPartPicker part list /
Price breakdown by merchant
CPU: Intel Core i5-4440 3.1GHz Quad-Core Processor ($168.99 @ NCIX US)
Motherboard: ASRock H97M PRO4 Micro ATX LGA1150 Motherboard ($74.99 @ Newegg)
Memory: G.Skill Ares Series 8GB (2 x 4GB) DDR3-1600 Memory ($54.99 @ Newegg)
Storage: Seagate Barracuda 1TB 3.5" 7200RPM Internal Hard Drive ($50.49 @ OutletPC)
Video Card: EVGA GeForce GTX 970 4GB ACX 2.0 Video Card ($334.98 @ SuperBiiz)
Case: Cougar Spike MicroATX Mini Tower Case ($29.99 @ Mwave)
Power Supply: Antec Neo Eco 520W 80+ Bronze Certified ATX Power Supply ($52.98 @ OutletPC)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer ($14.98 @ OutletPC)
Operating System: Microsoft Windows 8.1 (OEM) (64-bit) ($89.98 @ OutletPC)
Monitor: Acer G227HQLbi 60Hz 21.5" Monitor ($119.99 @ Micro Center)
Wireless Network Adapter: Rosewill N600PCE 802.11a/b/g/n PCI-Express x1 Wi-Fi Adapter ($19.98 @ OutletPC)
Keyboard: Logitech MK120 Wired Slim Keyboard w/Optical Mouse ($11.99 @ NCIX US)
Total: $1024.33
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-12-06 10:55 EST-0500
This is a 'three year plus' system.
As a teacher, I'm a 'professional', but we all live to help others on this board.