Power Supply for New PC

vetraptor

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Nov 12, 2007
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I can see it's been asked alot, but trying to figure out what I need. Power Supply calculator said I needed about 450W of power, but also have seen watts are irrelevant.

What I'm going to be running is:

EVGA 680iSLI LT MB
Antec 900 Series Gamer Case
BFG 8800GT card, will SLI eventually, but not right now
Intel E6850 3.0Ghz Dual Core
2 WD SATA Hd's
1 DVD Drive
1 DVD-RW not sure of models yet.

What I am looking at is this http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=371926
It's a CoolerMaster 650W power supply. It's just a really low price and was hoping someone could tell me if this would be enough?

And one other silly question, is there going to be big difference in my electric bill from my current 500W if I have to go higher to a 750?
 

einstein4pres

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Oct 11, 2007
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Power supplies only deliver the power that is needed. The only take in what they need to deliver the correct amount of power. Depending on efficiency, this may be quite different.

As for your electricity bill, consider buying a high efficiency power supply. Power supplies are most efficient when operating at roughly 50% of capacity, and are better in the 50% to 100% range than in the 0 to 50% range. More efficient power supplies also generate less waste heat.

High efficiency power supplies are frequently rated as "80PLUS", which offer 80% efficiency or better from 20% load to 100% load.
 

XMSYellowbeard

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Nov 2, 2006
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8800GTs are going to use about 100-120w under full load. So, 2 in SLI will pull about 10a at 12v max. So, you have 20amps right there. You CPU if OCed could easily pull another 100w so about 8-10 more there. Add in HD etc and OCing and IMO, you need a PSU with a mimimum of 40a on the 12v rail. This way, even at full 100% load, you system will pull about 65%-75% of the max capacity of the PSU. You don't want a PSU operating at much more than 75% full load for long periods of time.