Hiow do you know what power you you need

[xSan]

Hi I need help getting which power supply i need because i am building a computer and i need help getting a power supply, it would be very helpful if can help me

my specs:
lighting-color-change - Remote Control Color Change LED Light Strip

Motherboard: MB-ATX-msi-z270-sli-plus - MSI Z270 SLI PLUS with Integrated Wireless AC

Processor: cpu-intel-i7-7700-KB - Intel® Core™ i7 7700 3.6GHz/4.2GHz Turbo QUAD Core CPU w/ Hyperthreading 8MB L3 Cache

Processor Cooling: cooling-intelstock - MAINGEAR Certified Intel® Retail Cooler

Memory: mem-kingston-16GB-2x8GB-2666 - 16GB HyperX® FURY™ DDR4- 2666 (2x8GB) [Dual Channel]

Graphics Card: gpu-amd-radeon-570-4GB - AMD® Radeon™ RX 570 4GB GDDR5 with FreeSync™

Operating System Drive: hdd-samsung-850evo-250 - [SSD] 250GB Samsung® 850 EVO [520MB/s Sequential Reads]

Optical Drive Two: opt-asus-SDRW08D2SUBGACI - 8X Asus® DVD Burner External USB 2.0

Audio: audio-integrated-hd - On Board High Definition 8-Channel Audio

 

[CountMike]

https://outervision.com/power-supply-calculator
http://www.coolermaster.com/power-supply-calculator/
Add 25 - 50% to that figure

 

[sm620]

I would think for one graphics card 500 Watts or up would be fine. Like Count Mike said, you can always use an online calculater too. I suggest finding one in your wattage then check the reviews and calculate the 1 and 2 star as DOA then compare that with the 3 and up to come up with a figure representing fail rate. with power supplies not affecting the performance of a modern computer, reliability is my main concern when buying one. I recently bought a G3 from EVGA because my old one had gone for about 5 years with heavy use.

you shouldn't need more than 500W. To complicate things if you buy one with a certain efficiency raiting, you'll sometimes notice that they peak in efficiency at certain wattages which usually occur around 50 to 80% load, so I would personally not recommend buying the biggest ones for normal computers like I've seen some people do.

 

[10tacle]

Target about 75% of load use on your system with a PSU that is Bronze or Silver in efficiency rating (80% for Gold or Platinum). To give you an idea of your GPU use, Anandtech saw total system wattage consumption of ~300W while testing with Crysis 3 (a heavy GPU hitting game). This was their system test bed:

CPU: Intel Core i7-4960X @ 4.2GHz
Motherboard: ASRock Fatal1ty X79 Professional
Power Supply: Corsair AX1200i
Hard Disk: Samsung SSD 840 EVO (750GB)
Memory: G.Skill RipjawZ DDR3-1866 4 x 8GB (9-10-9-26)
Case: NZXT Phantom 630 Windowed Edition