Is the wattage calculator on PCPartPicker accurate?

[TopWargamer]

I usually use Newegg's power supply calculator when finding parts for a build for someone, but lately (for me) it's been down. PCPartPicker does have a wattage calculator built in, but I'm not sure how accurate it is. 

 

So is the PCPartPicker wattage calculator accurate? 

[Kirihuna]

I thought it was suppose to be an estimate based on the reported wattage on product pages, etc.

 

I would say it should be within like 5%.

[Stephie_Girl]

This one: http://www.extreme.outervision.com/psucalculatorlite.jsp Is pretty accurate.

[coen113]

just see the tdp, calculate a 10% overhead, and thats the minimum watt powersupply i recommend

[TopWargamer]

I thought it was suppose to be an estimate based on the reported wattage on product pages, etc.

 

I would say it should be within like 5%.

Oh ok, thanks. 

[MG2R]

I always use this formula to calculate my PSU:

 

[(cpuTdp + gpuTdp) * 2 ] + [(numberOfGpus -1) * gpuTdp]

 

Works every time.

[DLM_012]

just see the tdp, calculate a 10% overhead, and thats the minimum watt powersupply i recommend

 

That's similar to what I do. Typically I add up the TDP of the CPU and GPU and then add about 50-75W for a few other parts and OC'ing headroom. That method hasn't failed me once yet.

 

 

I always use this formula to calculate my PSU:

 

[(cpuTdp + gpuTdp) * 2 ] + [(numberOfGpus -1) * gpuTdp]

 

Works every time.

 

That's not too bad either ^^^

[MG2R]

That's similar to what I do. Typically I add up the TDP of the CPU and GPU and then add about 50-75W for a few other parts and OC'ing headroom. That method hasn't failed me once yet.

 

50-75 watt seems rather low for overcloking and the rest of the system combined. I guess that if your PSU is qualitative, it should be able to cope with being run borderline. Since it hasn't failed on you, I can only assume it works

 

The reason I prefer my technique is that it usaually makes your PSU run at or near it's maximum efficiency under load.

[Fetzie]

I always use this formula to calculate my PSU:

 

[(cpuTdp + gpuTdp) * 2 ] + [(numberOfGpus -1) * gpuTdp]

 

Works every time.

 

Why are you multiplying the CPU and GPU tdp times two?

 

So say you had a 2500K and a pair of 7950:

(95+225)*2 = 320*2 = 640

(2-1)*225 = 225

 

640+225 = 865W.

 

That is WAY "over budget". You can run 2xCF/SLI on a 650W PSU if it can supply ~600W on the 12V rail (and if it can't, it isn't worth the money).

PSU_Wattage = (((CPU_tdp*2)+GPU_tdp)+((sum_GPU-1)*GPU_tdp)) 

would be closer to reality IMO.

__________________________________________

 

My general rule of thumb:

300W for an APU system without a discrete graphics card

450W for a CPU + low - mid-class GPU

550W for a CPU + single mid to high-end GPU

650-750 for CPU + 2x CF/SLI or dual-chip GPU (650 will work on modern high-end cards but very little head-room if also overclocking the GPUs)

750+ for CPU + 2-4x CF/SLI

[nightlitezzz]

Probably not, however the LInusTechTips Community Wattage Calculator (LTTCWC) is.

[TopWargamer]

I always use this formula to calculate my PSU:

 

[(cpuTdp + gpuTdp) * 2 ] + [(numberOfGpus -1) * gpuTdp]

 

Works every time.

Doesn't like too bad of an idea. I'll have to remember to use this formula next time. 

[MG2R]

Why are you multiplying the CPU and GPU tdp times two?

 

So say you had a 2500K and a pair of 7950:

(95+225)*2 = 320*2 = 640

(2-1)*225 = 225

 

640+225 = 865W.

 

That is WAY "over budget". You can run 2xCF/SLI on a 650W PSU if it can supply ~600W on the 12V rail (and if it can't, it isn't worth the money).

PSU_Wattage = (((CPU_tdp*2)+GPU_tdp)+((sum_GPU-1)*GPU_tdp)) 

I factor in a substantial overclock and, as said before, this makes your PSU operate at peak efficiency under load (~50-60% usage)

 

That formulae you posted does seem fine as well. In the end it all boils down to how much 'extra' you want to keep in store.

[Honeydiddle]

Just add 10% to what it says to be sure

[ericlee30]

This one: http://www.extreme.outervision.com/psucalculatorlite.jsp Is pretty accurate.

That ones far from being accurate, it told me i utilize 1076W from the wall but I actually only pull 965W from the wall. That is with an actual Watts meter

[epkoc]

no, it overestimates the wattage a bit, in case you have a poor quality power supply

[lukeptba]

no, it overestimates the wattage a bit, in case you have a poor quality power supply

Or... leaves room for some expansion.

[Blade of Grass]

That ones far from being accurate, it told me i utilize 1076W from the wall but I actually only pull 965W from the wall. That is with an actual Watts meter

But it takes into account the system running full load with your HDD spinning up etc. It may not be 100% accurate, but it's better to over estimate than under.

[ericlee30]

But it takes into account the system running full load with your HDD spinning up etc. It may not be 100% accurate, but it's better to over estimate than under.

That is very true, i would rather it over estimate then be less then what i need.

[iAsuno]

Why are you multiplying the CPU and GPU tdp times two?

So say you had a 2500K and a pair of 7950:

(95+225)*2 = 320*2 = 640

(2-1)*225 = 225

640+225 = 865W.

That is WAY "over budget". You can run 2xCF/SLI on a 650W PSU if it can supply ~600W on the 12V rail (and if it can't, it isn't worth the money).

PSU_Wattage = (((CPU_tdp*2)+GPU_tdp)+((sum_GPU-1)*GPU_tdp))

would be closer to reality IMO.

__________________________________________

My general rule of thumb:

300W for an APU system without a discrete graphics card

450W for a CPU + low - mid-class GPU

550W for a CPU + single mid to high-end GPU

650-750 for CPU + 2x CF/SLI or dual-chip GPU (650 will work on modern high-end cards but very little head-room if also overclocking the GPUs)

750+ for CPU + 2-4x CF/SLI

number of gpus minus 1

so you would have 545

edit: you used the formula wrong. [(95+255)*2]+[(1-1)*255]

700+0=700