Maximum power on minimum power(400w)

aliasautumn

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May 23, 2011
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After two years with my machine I have decided that she needs a graphics upgrade. When using two "power supply calculators online" it gave estimates for the power consumption of my system to be ~260 watts and ~310 watts, which is way to large of a gap for me for to comfortably accept.

Processor: Intel Core i7-2600K Sandy Bridge 3.4GHz
Motherboard: ASUS P8P67 PRO (REV 3.0) Motherboard
Memory: 4 x ADATA XPG Gaming Series 2GB DDR3 SDRAM 1600
Graphics: EVGA GeForce GT 220 1GB Video Card
Cooler: Cooler Master Hyper 212 Processor Cooler
Hard Drive 1: SAMSUNG Spinpoint F3 500GB 7200 RPM 16MB
Hard Drive 2: SAMSUNG Spinpoint F3 1TB 7200 RPM 32MB

Power Supply: Corsair CMPSU-400CX 400W

The question comes at whether I can safely change out my GT 220, for a much meatier card. I think 7770 is my baseline, though I'm looking for the fastest card possible under $200. I know I can upgrade the PSU, but if I a 7770 works on this machine then I don't see a reason to.

Any input would be nice, and thanks everyone for taking the time to read the above.
 

aliasautumn

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May 23, 2011
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Interesting that the GT 220 actually draws more power than a 7750. I wonder why it is listed as compatible in a 300w system while the 7750 is recommended for 400w or greater systems.

I'm actually considering just picked up at 7750 to be safe as I didn't expect the difference between the 7750 and 7770 to be a whole 25w.

Is there any way to know what my limit is for the power consumption, because otherwise playing it safe with a card that uses about the same power may be the route I take.
 

aliasautumn

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May 23, 2011
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Thanks a1blaster. Apparently the i5 2400 and i7 2600k also have identical max TDP according to intel's site.

So that 300W (25A?) pull is from the 12V line alone correct?
Seeing at I have my 2600k stock right now, research shows that it is only pulling 90w to 95w. I guess that now leaves me 100w to 105w to safely work with?

Thanks for the responses. Actually learning quite a bit right now. :D
 
if you look at the power supply label is have max output for each line and should = 400w. and it the 12v line max amps and wattage you look at. (cpu plus gpu). the cd-rom and hard drive do use a little bit of the 12v line but it only a few watts of power.