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Chosing right Wattage for built.

Last response: in Components
May 29, 2012 4:49:36 AM

Hey everybody,

I'm trying to figure out whether I can use my old Power supply( 1 year- 550W)
for my new built. I tried already to calculate the Power needed but I ended up with 335 W. I think that is way to less.
I jope nothing is missing

Here my built:

CoolerMaster 690 II Advanced
Intel Core i5 2500K
2048MB Sapphire Radeon HD 7850
8GB G.Skill Ripjaws DDR3-1600
Noctua NH-D14 AMD and Intel
1000GB Western Digital Caviar Green WD10EARS 64MB 3.5"
ASRock Z77 Extreme4 Intel Z77 So.1155
60GB OCZ Agility III 2.5"
LG Electronics GT60N Slim DVD+-R/RW

If you have any improvements for this built you are also welcome to post them ;) 

Would be great if somebody can figure that out or help me to find my mistake.

Thanks everybody

More about : chosing wattage built

a c 158 ) Power supply
May 29, 2012 11:57:28 AM

What is the make/model of your PSU? Can you use the DVD-R from your old PC? Are you re-using the old case? Does your 335W calculation include OCing? If not, then that number actually looks a bit high for a single 7850 system; actual power usage is likely to be closer 275-300W at full load.

A system with a single HD 7850 requires a 500W PSU with at least 30A on the 12V rails and one 75W 6-pin PCIe power connectors. Bottom line, a good quality 550W PSU is more than sufficient to power your system and moderate OCs to the GPU and CPU.
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a c 243 ) Power supply
May 29, 2012 12:17:08 PM

Even if you could manage to overclock to 5Ghz your 2500K wouldn't draw as much power as this overclocked I7-965
254 watts from the wall when running a gamelike application, with a factory overclocked 7850
With a good quality 550 watt psu you could overclock till the thing is ready to let loose it's magic blue smoke and not have to worry about power
May 29, 2012 3:49:48 PM

hey thank you all for that answers!!

I have a Bequiet PSU at home. I bought it 02/2011. Do guys want to have the exact name?

No I won't re-use my case and DVD-R from my old PC. The DVD-R has an IDE port. The case is too unorganized and old ;) 

I get for the DVD-R the (LG Electronics GT60N Slim DVD+-R/RW)
and for the case (CoolerMaster 690 II Advanced).

No the calculation of 335W did not include the OC-ing, because I don't now the wattage of a 7850 or 2500k when it is overclocked.
I won't buy anything overclocked. But I plan to oc the 7850 and 2500K later on...

Thanks for all your support!
a c 158 ) Power supply
May 29, 2012 5:06:41 PM

Bequiet does have some good PSUs. They have about 4-5 550W models; what is the model number of yours?
May 30, 2012 3:23:28 AM

Rugger said:
Bequiet does have some good PSUs. They have about 4-5 550W models; what is the model number of yours?

Cause I am not home right now I try to get my brother to give me the information...
I hope I will get them tomorrow!

Best solution

a c 158 ) Power supply
May 31, 2012 4:38:41 PM

It is a decent PSU and more than sufficient for your planned build. The 7850 is not a power-hungry part; a system with a single 7850 requires a 500W PSU with a total of 28A on the 12V rails and one 75W 6-pin PCIe power connector.
May 31, 2012 11:28:33 PM

Best answer selected by Exterminans.
a b ) Power supply
June 1, 2012 9:11:11 AM

This topic has been closed by Mousemonkey