[SOLVED] Why BeQuiet PSU calculator differs?

babicdusko

Reputable
Dec 15, 2018
21
0
4,510
I7-4770, GTX1060, DDR3x2, SATAx2

BeQuiet states "Your maximum wattage requirement 242W" while Coolermaster, Seasonic and OuterVision all give 342W. Based on the calculator it suggests a few PSUs, among the others Pure Power 400W and states the load 60%.

Is the difference in MB consumption? Shouldn't it take MB into consideration as well?
 
Solution
Most Calculators over estimate to make sure you purchase a PSU with enough power.
This is the answer.

1060 drains up to 140-145 W on full load
Your CPU will consume about 100W on full load
Then comes the motherboard, hard drives, optical drive, etc etc.

You must count like 280+W stable power delivery on Your PSU. This is just dangerous at the worst case scenario (which might never happen)

maziech

Respectable
Feb 18, 2019
364
45
1,840
I'm adding the GTX 1060 to the PC. I wonder if my current 350w will do job. According to BQ calculation it should be plenty.
Probably nope.

Your 350W is surely an old construction and MAYBE not the one You can rely on, when it comes to full load (can You post the PSU model please?)

You pick a psu to match about 60-80% of it's max value. That would be around 280W max, which is dangerously close to the maximum power consumption of Your setup. If it's not reliable PSU, You may encounter some problems or even damage Your hardware.
 

maziech

Respectable
Feb 18, 2019
364
45
1,840
AFAIK it's not that bad PSU, but i'm not an expert, if it comes to power supply (keep that in mind and ask someone else to make sure).

This thing shoud work somehow with 1060 and Your setup, but it's a risky plan. I'd say You are on the edge of stability ;-)

Keep in mind that:
  • it is an old, used PSU and doesn't have to perform exactly as a new one (i'm guessing it's working for 5+years in Your rig for now)
  • it might be pushed to the limit on full load, which is just risky. At full load You might experience problems with Your hardware.
I'd change to some mid-budget 450W. They are not that expensive - you can be OK for additional 50$, it's not worth to stick to the old one at all costs.

The worst thing that can happen here is video card / mobo damage. You don't want to risk it for 50$.
 
Last edited:

babicdusko

Reputable
Dec 15, 2018
21
0
4,510
I ordered a Seasonic SS-520GB and will install it in a few days. However, I'm still tremendously curious why is there a 100w difference in PSU calculator? Is BeQuiet underestimating or the others are overestimating? As I said a BQ suggests 400w PSU with 60% load. That means 350w could work with 70% load. Curious indeed. :)
 

maziech

Respectable
Feb 18, 2019
364
45
1,840
Most Calculators over estimate to make sure you purchase a PSU with enough power.
This is the answer.

1060 drains up to 140-145 W on full load
Your CPU will consume about 100W on full load
Then comes the motherboard, hard drives, optical drive, etc etc.

You must count like 280+W stable power delivery on Your PSU. This is just dangerous at the worst case scenario (which might never happen)
 
Solution

babicdusko

Reputable
Dec 15, 2018
21
0
4,510
Thanks. Just checked BQ calculator again. For i7-4770 and GTX 1060 only it states maximum requirement 204w. Official manufacturer TDP is 84w + 120w=204w. However some tests for the components state max 95w+135w. Seems the difference come from the CPU turbo. Is TDP power required only for CPU, then the fan will use some power as well or it's already calculated into official TDP? Now I'm really curious.
 
I ordered a Seasonic SS-520GB and will install it in a few days. However, I'm still tremendously curious why is there a 100w difference in PSU calculator? Is BeQuiet underestimating or the others are overestimating? As I said a BQ suggests 400w PSU with 60% load. That means 350w could work with 70% load. Curious indeed. :)

You will need to talk to whoever made those wattage calculators. There is no way for anyone else to know why or how they do what they do when they do it.
Calculations are done at the back end on the server, then you get the data. We can't see the back-end code.

If you check on the video card vendor page and get the recommended wattage PSU or higher, you will be OK. Trying to save $10 to get a lower wattage PSU is no good.
 

Math Geek

Titan
Ambassador
my experience has been that companies that make crappy psu's tend to have calculators that way over-estimate. i assume this is due to the fact that they know their units are junk and it would take one of their "600w" units to do what a quality 450w one can do.

add in what hang said about what they were considering when making the calculator and you get wildly different numbers across various calculators. i do the math myself and don't bother wasting any brain cycles on figuring out what they were thinking when they made those. pcpartpicker is pretty good with adding up wattage of the various parts, though of course they are based on stock settings. anytime you overclock ANYTHING it will effect the numbers. if you plan on overclocking the cpu/gpu/ram then do some homework on what kind of power draw those parts saw when oc'ed and add that into your power needs. every part is different but some quick searching should turn up a few reviews that can give you a basic idea how much power is added with overclocking.

it can be little or it can be VERY significant depending on the part.