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PSU overkill?

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June 1, 2008 3:23:08 PM

I just posted this elsewhere in the forums (where it didn't belong). Sorry 'bout that.

I'm starting a new system build with an eye towards keeping it as energy efficient as I can without overly sacrificing capability.

E7200
Gigabyte EP35-DS3L
MSI 9600GT
8 Gigs OCZ DDR2 800
640 Gig WD Caviar HD
Asus 22X DVD burner

This is going in an Antec Sonata Designer case that came w/an Earthwatts 500W 80 plus certified PSU. My question is: this PSU is clearly overkill for the system. Does it defeat the energy savings of the components? Would it make any sense to "downgrade" to a 300W PSU, or will it still run efficiently?

Thanks!

More about : psu overkill

June 1, 2008 5:38:15 PM

Found this review. Hope it sheds some light:

http://www.virtual-hideout.net/reviews/Antec_Earthwatts...

"during the testing phase I was able to use more than 50% of the power supply's rated wattage. During that testing phase, the efficiency of the EarthWatts EA-500 was over the required 80% and was actually 97% on the PF. I also checked the EarthWatts EA-500 at 20% load or 100W and the efficiency was 98% and finally with no load except for a power supply tester, it drew 8W and had a 91% PF"
a b ) Power supply
June 1, 2008 6:00:40 PM

a PC will pull whatever power it needs from a PSU, if the PSU can't provide it you are in trouble if it can you are not. Most PSU,s will have an efficiency curve which tells you what efficiency they are running at at what power level. Most PSU's become most efficient at >50-60% of they rated value.

Note that the drop off in efficiency may not have much effect. Dropping from 90% to 85% at 250W because you went from 400W to 500W will 'only' increase power usage at the wall by 5%, approx 12W. A larger PSU will also run cooler than one that is being stressed this may reduce fan speeds, which could save a couple of watts.
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June 1, 2008 9:08:27 PM

callousdigits said:
I just posted this elsewhere in the forums (where it didn't belong). Sorry 'bout that.

I'm starting a new system build with an eye towards keeping it as energy efficient as I can without overly sacrificing capability.

E7200
Gigabyte EP35-DS3L
MSI 9600GT
8 Gigs OCZ DDR2 800
640 Gig WD Caviar HD
Asus 22X DVD burner

This is going in an Antec Sonata Designer case that came w/an Earthwatts 500W 80 plus certified PSU. My question is: this PSU is clearly overkill for the system. Does it defeat the energy savings of the components? Would it make any sense to "downgrade" to a 300W PSU, or will it still run efficiently?

Thanks!

Your good with your EA500D
I actually have the same case and changed-out the EA500 for a Corsair HX520.
Also remember you'll be running 8 gigs of OCZ ram.
June 2, 2008 2:26:44 AM

yeah thats fine with some room for improvement. PSUs are fine as long as they are quality and you consistantly pull 25%-75% of their rated wattage they will be ok. It is those idiots that buy 1000w PSUs for a lower end build then whine when it dies a few months later because it usually idles below 250w...
!