+12v amps and gfx cards

[wiskers157]

I am thinking about running two graphics cards, and each have a minimum requirement of 12v amps, obviously.

My question is does my psu need to have enough for both of the minimum requirements combined? or does it just need to satisfy the maximum required amps?

gtx 260 requires a min of 500 watt with +12v @ 36 amps
geforce 210 requires 300 watt with +12v @ 18 amps

Do i need a PSU with a +12v@54 amps or more, or one with +12v@36 amps or more?

Current PSU is CORSAIR 550W - Model CMPSU-550VX - +12V@41A

 

[tecmo34]

You will be fine with a 550W PSU with the GTX 260 & GeForce 210.

 

[wiskers157]

so does that mean i only need a max of 36 amps?

 

[tecmo34]

You look at the total amps of the first card and the total system requirements. You add additional total wattage of a few 100 for the additional card. However, the GeForce basically just runs on the PCIe power, so it doesn't take much at all.

If you where running two GTX 260's, I would recommend going with a minimum of a 650W power supply. Check the PSU sticky for more links and info...

 

[wiskers157]

so the wattage and amps of both cards requirements aren't simply added together to find the requirements?

I guess im trying to ask why i ignore the amp requirement on the 210.

Sorry if im being inconvenient.

 

[tecmo34]

You don't have to added them together to get the required AMPs... Read through this thread and you get an understanding... http://www.tomshardware.com/forum/279391-28-power-requirements-specs-popular-graphic-cards-guide

 

[ko888]

The GeForce GTX 260 will draw 15.2 Amps max from +12 Volt rail

The GeForce 210 will draw 2.54 Amps max from +12 Volt rail

That's a total of 17.74 Amps max from the +12 Volt rail for both graphics cards.

Your Corsair CMPSU-550VX with its ability to provide 41 Amps on its +12 Volt rail is more than enough.

 

[wiskers157]

Thanks!!, just wondering though, why does it only draw 17.74 amps if they require a larger amount on the psu?

 

[wiskers157]

Best answer selected by wiskers157.

 

[ko888]

The GeForce GTX 260 will draw 2.5 Amps at idle from the +12 Volt rail

The GeForce 210 will draw 0.5 Amps at idle from the +12 Volt rail

Together they will draw anywhere from 3.0 Amps at idle to 17.74 Amps under full GPU load from the +12 Volt rail.

If you were to overclock the graphics cards the current drawn will increase since they will consume more power.

Your Corsair CMPSU-550VX will provide up to 41 Amps on the +12 Volt rail only when needed. There are other system components, other than the graphics cards, that will also draw current from the +12 Volt rail.

 

[wiskers157]

what else draws from the +12 volt rail?