Radeon PSUs and Power Usage

cassinni

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Mar 24, 2013
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Hi,

i want to buy a radeon 7780 for my old desktop pc.(matx)
I have several questions regarding that.

My Tower is a Antec Fusion Remote.(original 400w PSU)
Mainboard P5N7A-VM,8GB DDR2,Intel Core2 Duo E8400 @ 3.00GHz.
The CPU cooler is a SILVERSTONE NT01-E. I have to extra fans running
in the tower. Nothing has ever been overclocked or modified. I use the gforce 9300 onboard psu.

Now i want to switch to the 7780 1GB or 2GB.

I read it needs 500W at least, so i wonder if it works on my system?
What does the watt number on a psu mean? does it mean my 400w uses 400 all the time or just if i have a million programs running at the same time?
Do you recommend that card or is it overkill for my old system and i should get something cheaper (7750) instead?

thanks
 
Solution


I wouldnot say that but ya my guess is you could use 90% of that 7850 if you could overclock speacialy if you game on 1920x1080p.

When your pc asks more than the power supply is capable off than the power supply shuts down.

With 7770 or 7850 your PC will never need more than 400 watt.

imomun

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Feb 17, 2013
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400W means your PC power supply is capable of delivering a combined 400 Watt power. In most cases normal day to day usage, Computer doesn't require more than 100-150 Watt but during gaming It can require upto 300Watt or even more. And always you need to have 100-250watt more watts extra than you need to be safe.

Get a HD7770 instead, anything above will give you occasional CPU bottolneck, unless you can overclock the cpu to 3.8GHz or something.
Thanks
 

cassinni

Honorable
Mar 24, 2013
5
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10,510
thanks for your help.
So you are saying I could use a 7850 if i could oc the cpu because as of right now the weak cpu would limit the 7850 performance?

What would happen if my system at one point needs more then the max. available 400w?
 

chromic

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Jan 6, 2013
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worst case scenario is, the PSU "blows up" and fries your mobo, gpu, cpu ram, essentially your whole pc.

but my guess is, its just going to shut down

 

imomun

Honorable
Feb 17, 2013
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11,660


I wouldnot say that but ya my guess is you could use 90% of that 7850 if you could overclock speacialy if you game on 1920x1080p.

When your pc asks more than the power supply is capable off than the power supply shuts down.

With 7770 or 7850 your PC will never need more than 400 watt.
 
Solution