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Power consumption?

post #1 of 5
Thread Starter 
So after having watched many a build video and seen so many high end PC's using like 1000-1200w power supplies, and even reading threads where people say "yeah I'm pulling about 900w from the wall" I started thinking it may be time to get a new PSU, especially since I am thinking about getting a second 290x. But first I wanted to see what I was actually pulling from the wall, so I picked up a Kill-A-Watt power meter (just plugs into the outlet and plug your device into that) to test. Now I like to think and tell myself that I have a pretty high end machine, and I was figuring it would be pulling quite a bit. So to list out everything that takes power:

i7-3770 3.4ghz
R9 290x
8GB Crucial Ballistix 1866 (2 sticks)
2x 2TB 7200rpm HDD
2x 2TB 5400rpm HDD
2x 240GB Seagate 600 series SSD's
1x Blu Ray Burner
3x 120mm fans
2x 140mm LED fans
ASrock Extreme3 Z77 mobo
Laing D5 Vario pump

All of this is running on a Corsair HX750w PSU.

Now, to max out everything, flipped all the fans to 100%, accessed a file on each of the drives to make sure they are spun up, prime95 for 100% cpu and also started a max Heaven benchmark for GPU. Then i even cycled the blu ray drive. Now all of this going on I was watching the display on the kill a watt. I let everything run for about 25min to make sure all the components had a chance to warm up. The HIGHEST I saw the power spike to was 398W (from the wall). So if we take 400W * 3% (margin of error for kill a watt) = 412W from the wall. Now 412W * 87% (lowest efficiency for HX750) = 358W the PSU is actually supplying to the system.

Am I missing something? The 290x states it requires a minimum of 750W power supply? Why? And what in gods name do people have in their PC that make them claim to pull 900w from the wall? I guess I could see getting a bigger PSU to cut back on PSU temps (therefore not requiring the psu fan to come on and reducing noise) because one thing I have noticed is that the fan in my PSU actually comes on now because I'm pulling more power than before (previously with 6870 + i5-750 I was only pulling about 280W under load and the PSU didnt run the fan very much at all)

Can someone clear up the confusion for me?

Thanks
post #2 of 5
These guy's are probably folding or coin mining with heavy over-clocked systems! But yeah, look at my rig for instance. I am running it all on an 860w!
X79-GCN
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CPUMotherboardGraphicsRAM
Intel 3930K 4.5GHz HT GIGABYTE GA-X79-UP4 AMD R9-290X GEil Evo Potenza DDR3 2400MHz CL10 (4x4GB) 
Hard DriveCoolingCoolingCooling
Samsung 840 Pro 120GB EK Supremacy (CPU) NF F12's P/P (360 Rad)  NF A14's (420 Rad)  
CoolingCoolingCoolingCooling
XSPC Chrome Compression Fittings EK RES X3 150 Primochill PremoFlex Advanced LRT Clear 1/2 ID EK-FC (R9 290X) 
CoolingCoolingCoolingOS
EK D5 Vario Top-X  Phobya G-Changer V2 360mm Phobya G-Changer V2 420mm Win 10 x64 Pro 
MonitorKeyboardPowerCase
BenQ XR3501 35" Curved Corsair Vengeance K90 Seasonic X-1250 Gold (v2) Corsair 900D 
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X79-GCN
(22 items)
 
  
CPUMotherboardGraphicsRAM
Intel 3930K 4.5GHz HT GIGABYTE GA-X79-UP4 AMD R9-290X GEil Evo Potenza DDR3 2400MHz CL10 (4x4GB) 
Hard DriveCoolingCoolingCooling
Samsung 840 Pro 120GB EK Supremacy (CPU) NF F12's P/P (360 Rad)  NF A14's (420 Rad)  
CoolingCoolingCoolingCooling
XSPC Chrome Compression Fittings EK RES X3 150 Primochill PremoFlex Advanced LRT Clear 1/2 ID EK-FC (R9 290X) 
CoolingCoolingCoolingOS
EK D5 Vario Top-X  Phobya G-Changer V2 360mm Phobya G-Changer V2 420mm Win 10 x64 Pro 
MonitorKeyboardPowerCase
BenQ XR3501 35" Curved Corsair Vengeance K90 Seasonic X-1250 Gold (v2) Corsair 900D 
MouseAudio
Logitech G400s Senn HD 598 
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post #3 of 5
Im not sure how you got your power consumption so low, just running Prime95 alone on my system sucks 498w from the wall with my sig rig, was around 400w from the wall with a 4770k.

Load up both 290x's and my cpu, and my meter is showing 1.3kw draw. Overclocked CPU and +100mv and overclocked gpus of course too, ive done a study before and saw voltage added to the 290x almost doubles is power draw. That said, just running BF4, i draw between 850-1000w from the wall.
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post #4 of 5
Thread Starter 
Quote:
Originally Posted by ShortySmalls View Post

Im not sure how you got your power consumption so low, just running Prime95 alone on my system sucks 498w from the wall with my sig rig, was around 400w from the wall with a 4770k.

Load up both 290x's and my cpu, and my meter is showing 1.3kw draw. Overclocked CPU and +100mv and overclocked gpus of course too, ive done a study before and saw voltage added to the 290x almost doubles is power draw. That said, just running BF4, i draw between 850-1000w from the wall.


Has to be your overclocks for sure. My previous post was slightly inaccurate because at the time, I had forgotten I was running a slight overclock on the GPU core and mem. I have since increased that overclock to 1160mhz/1450mhz @ 1.375v. So here are my actual numbers:

idle- 95W
CPU load only- 175W
GPU load only- 320W
GPU + CPU load- 360W
GPU OC load only- 395W
GPU OC + CPU load- 445W

The overclock on the 290x alone draws an extra 75W.
Edited by BadDopey - 3/21/14 at 11:24pm
post #5 of 5
Quote:
Originally Posted by BadDopey View Post

Has to be your overclocks for sure. My previous post was slightly inaccurate because at the time, I had forgotten I was running a slight overclock on the GPU core and mem. I have since increased that overclock to 1160mhz/1450mhz @ 1.375v. So here are my actual numbers:

idle- 95W
CPU load only- 175W
GPU load only- 320W
GPU + CPU load- 360W
GPU OC load only- 395W
GPU OC + CPU load- 445W

The overclock on the 290x alone draws an extra 75W.


Yeah my idle alone is 242w
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