How Much Power Do I Need?

[Sanvich]

The computer consists of the following components I've already purchased:

• 
  GIGABYTE AORUS GeForce GTX 1080 Ti DirectX 12 GV-N108TAORUS-11GD 11GB 352-Bit GDDR5X PCI Express 3.0 x16
  
  Western Digital WD Gold 6TB HD - 7200 RPM Class SATA 6Gb/s 128MB Cache - WD6002FRYZ
  
  Thermaltake Ring Silent 12 Blue LED 150W Intel/AMD 120mm CPU Cooler CL-P022-AL12BU-A
  
  CORSAIR Vengeance LPX 32GB (4 x 8GB) 288-Pin DDR4 SDRAM DDR4 2400 (PC4 19200) CMK32GX4M4A2400C14B
  
  ASRock Z270 TAICHI LGA 1151 Intel Z270 HDMI SATA 6Gb/s USB 3.1 USB 3.0
  
  Pioneer 16X BD-R 2X BD-RE 16X DVD+R 12X BD-ROM 4MB Cache SATA Blu-ray BDR-209DBK
  
  Intel Core i7-7700K Kaby Lake Quad-Core 4.2 GHz LGA 1151 91W BX80677I77700K
  
  SAMSUNG 960 PRO M.2 512GB NVMe PCI-Express 3.0 x4 Internal SSD MZ-V6P512BW
  
  Full ATX Case with approximately 10 Blue LED Case Fans (120mm and 230mm) and a Blue LED Light Bar.

I simply need to know how big of a power supply (in Watts) would I require to run smoothly?

 

[7sixes]

I suggest going to https://pcpartpicker.com/list/ and enter the above parts and see how many watts you need.

 

[Rexper]

This system uses 300 to 350w under a gaming load based on professional reviews. A 450w quality power supply would cut it, though 550w allows more comfortable headroom for further upgrades + opens options to better quality power supplies.

I suggest the EVGA G2, EVGA G3, CORSAIR RMx, or Bitfenix Whisper 550w.

 

[JackNaylorPE]

1. This is a very simple thing to determine ... 99.7% of the time your PSU requirements will be determined by your GFX card.

2. be aware that adding up your wattage is insufficient... take then number and multiply by say 1.25 at stick, 1.50 if serious overclocking.

3. One of the easiest ways is to see what nVidia says:

https://www.nvidia.com/en-us/geforce/products/10series/geforce-gtx-1080-ti/

Thermal and Power Specs:
91 = Maximum GPU Temperature (in C)
250 W = Graphics Card Power (W)
600 W = Recommended System Power (W)4
One 6-pin, One 8-pin = Supplementary Power Connectors

That tells ya 600watts, 600 + 250 if y want SLI. Now that applies to the referenrce card ... the Gigglebyte card uses a lot more power

https://www.techpowerup.com/reviews/Gigabyte/GTX_1080_Ti_Xtreme_Gaming/28.html

In peak gaming, it can hit 266 watts ... but overlcocking allows you to boost the power limit to 1505 leading to a theoretical 399 watts. Will ya see 400 watts out of this card, I strongly doubt it ... bit I would assume well above 250.

The reference cards have a 250 Watt TDP, 75 Watts is delivered though the PCIe slot, then 150+150 Watts through the and 8-pin PEG (PCI Express graphics) power connectors. Accumulated with the 12-phase GPU VRM design that means a board power design of 375 Watts. Gigabyte will allow you to increase that 250 Watt TDP towards 375 Watts by an extended power limiter. That's plenty spare for a nice tweak.

4. Guru #D does some nice "at the wall" testing and they write :

http://www.guru3d.com/articles_pages/gigabyte_aorus_gtx_1080_ti_xtreme_gaming_review,8.html

Here is Guru3D's power supply recommendation:

Nvidia GeForce GTX 1080 Ti - On your average system the card requires you to have a 600~650 Watts power supply unit.
Nvidia GeForce GTX 1080 Ti SLI - On your average system the card requires you to have a 800~950 Watts power supply unit.

If you are going to overclock your GPU or processor, then we do recommend you purchase something with some more stamina.

As above, considering that the card gives a potential of +125 watts and the CPU a potential 45 watts from overclocking ... if you intend to go big on the CPU and GPU OCs, id use a 750 watter.

CPU Overclocked 130
GPU Overclocked 325
MoBo 35
RAM 10
everything else 40

Thatz 540.... so where you might be inclined to say "Oh 550 is fine", you have to take into account that:

a) NEVER use anything else than the minimum system specs and nVidia says that's 600 watts.

b) the level of overclock you get depends on the quality of the signal with respect to voltage stability and electrical noise... there are also momentary peaks which, as an analogy, in audio folks refer to as clipping when the momentary wattage exceeds the rated wattage of the amplifier ... it doesn't sound good.

With a PSU, the quality of the signal decreases the closer the load gets to the rated voltage ... efficiency also takes a nose dive once you pass 50%. So you want to stay well away from this extreme if you want to achieve high stable overclocks.

 

[Wolfshadw]

Generally when making recommendations like this, I'll take the maximum power of the graphics card plus the Thermal Design Power (TDP) of the processor and add 30% over that. That gives plenty of power for other components as well as any possible over-clocks.

Your graphics card has two 8-Pin PCI-E power ports for a maximum of 375 watts (no, I don't believe it will ever actually use that much). The processor has a TDP of 91 watts for a total of 466 watts. Add 30% to come up with 605.8 watts. A 600 watt Power Supply would be my recommendation (same as the graphic card's recommendation).

-Wolf sends

 

[JackNaylorPE]

I agree with the 30% but that doesn't account for all the other devices or OC on the CPU (130-135 watts)