what PSU calculator to trust?

Saumya Dudeja

Reputable
May 17, 2014
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0
4,630
Hi, ;)
I have calculated the required supply for my PSU, and these 2 have a huge difference:
Asus calculator = http://support.asus.com/powersupply.aspx
According to this , I need 750 w PSU
And
This one = http://coolermaster.outervision.com
This shows 400w will be enough

My specs :
Processor : AMD Fx-8320
Motherboard: Asus M5A97 r2.0
Ram: G.Skill RipjawsX DDR3 8 GB (1 x 8 GB) PC RAM (F3-12800CL10S-8GBXL)
Graphics:Zotac nVidia 650 ti 2 GB DDR5 (Can go for 750 ti if it really saves power)
HDD:Seagate barracuda 500 GB ST500DM002

Please give me some quick advice I need to build my rig this moth only.
Thanks...
 
Solution
I don't trust any of them since they all seem to vastly overestimate your usage. The one I use is the Watts-Up-Pro ES, but a Kill-a-Watt will do just fine.

Generally for a single video card design these days any great 500 or good 550 will handle the machine with plenty of headroom. Your machine as listed is probably looking at using more like 320 watts from the wall (less being supplied to PC), or somewhere near there.

Traciatim

Distinguished
I don't trust any of them since they all seem to vastly overestimate your usage. The one I use is the Watts-Up-Pro ES, but a Kill-a-Watt will do just fine.

Generally for a single video card design these days any great 500 or good 550 will handle the machine with plenty of headroom. Your machine as listed is probably looking at using more like 320 watts from the wall (less being supplied to PC), or somewhere near there.
 
Solution

gn842a

Honorable
Oct 10, 2016
666
47
11,140
I don't trust any of them since they all seem to vastly overestimate your usage. The one I use is the Watts-Up-Pro ES, but a Kill-a-Watt will do just fine.

Generally for a single video card design these days any great 500 or good 550 will handle the machine with plenty of headroom. Your machine as listed is probably looking at using more like 320 watts from the wall (less being supplied to PC), or somewhere near there.

I don't think there's anything general going on. I had the startling experience of taking a Nitro RX 590 that had been repeatedly crashing for days, on an 850 watt Seasonic psu. Sounds like plenty right? Overbuying the psu right? I put it on a different computer with fewer peripherals and 1050 watts and it purrs like a kitten. This crashing-all-the-time psu was rock solid during Unigine High and Extreme tests. So, I'm thinking that in fact we are underbuying psus, and that's why there are a fair number of people complaining about the stability of their 570 - 580 - 590 series graphics cards. Go ahead and spec a computer without the psu. Then add 500 watts.

That, I think, is closer to the situation of these psus. The instability comes from the spikes in demand. The gpu puts out a spike demand for power, the psu says sorry can't do that, and your system goes down. "Buying for the spike" is very different from buying for the typical usage. People who benchmark and game have lots of spikes.

I've put my money where my mouth is I have a 1300 watt psu due to arrive tomorrow. Assuming it is a good unit (always a dicey thing to assume) we'll see what happens to the gpu performance when the available power is comfortably above the spike level. At one level I sort of hope that these gpus don't require bigger psus, because the cost of the psu is a real obstacle. But I think if folks are going to pursue power hungry psus they better understand that there might be two costs: One of the gpu, and the other for the psu.

Greg N