PSU Confusion

[jdice1980]

I have ordered an EVGA 8800 witha power supply, but my ongoing research into upgrading pcs has led to some concern. The requirements for the card say a minimum 450 watt with minimum of 30 amps on the 12v rail. However, the psu I have coming has two rails one with 18amps and one with 20....is this psu going to work? Or does the GPU hook to only one rail, and therefore will be short on power?

 

[lostandwandering]

What specific PSU is it? They want the combined +12v rails (don't just add the rails though).

 

[jdice1980]

http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=2974309

That is the supply....the Ultra X-Finity

 

[chookman]

Ultra is a Tier4 PSU and not highly recommended.

If you want a cheaper side PSU your better off with Antec or Thermaltake

 

[jdice1980]

Anyone want to actually answer the question? Or am a wasting my time looking for help here? Does the power from the two rails power the card, or just power from one rail.

 

[frozenlead]

the psu can power it (depending on what else you've got, but in general)...but considering it's cheapness, i don't think anyone here will guarantee how long it will actually last.

 

[jdice1980]

Thanks for the criticism that is exactly what I was looking for. You damn self righteous SOB’s

 

[teh_boxzor]

lol yeah it'll work.

 

[rockyjohn]

When the graphics card states the power requirement for the system, such as the 30 amp requiremnent in your case, you do add both rails on your psu together - so your has 38 amps which is plenty.
In addition, according to a JohnnyGuru, a respected site regarding power supplies, your PSU actually has only on leg or circuit even tho it says two because it has to separate connectors.
Further, JohnnyGuru rates the Infinity 600W energy efficient psu as a recommend sub- $150 unit.

 

[chookman]

Thanks for the criticism that is exactly what I was looking for. You damn self righteous SOB’s

Lol i sense a hint of sarcasm.

Yes the PSU will work, What i think you are not realising is the recommended 450W PSU is actually rated on the whole system not just the GPU as most would think.

http://www.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354

Here you will see the Ultra will draw ~163W which your looking at about 14amps on the 12v rail.

 

[chookman]

When the graphics card states the power requirement for the system, such as the 30 amp requiremnent in your case, you do add both rails on your psu together - so your has 38 amps which is plenty.

This is not always the case. It will do 18amps on one and 20amps on the other... but if they are in use at the same time, they may not do 38amps combined. This is a common mis-conception. Generally it will have listed on the manufacturers site

http://www.ultraproducts.com/product_details.php?cPath=52&pPath=383&productID=388

This shows a combined 420w on the 12v rails. Which actually translates to 35amps not 38 as stated.

 

[rockyjohn]

This shows a combined 420w on the 12v rails. Which actually translates to 35amps not 38 as stated.

I stand corrected. Thank you.

 

[lostandwandering]

Thanks for the criticism that is exactly what I was looking for. You damn self righteous SOB’s

Thanks I needed the laugh. :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

 

[altazi]

Hi Jdice1980,

Post your question in "The Other" forum. There are some very knowledgeable people there who will be happy to help you.

 

[chookman]

Hi Jdice1980,

Post your question in "The Other" forum. There are some very knowledgeable people there who will be happy to help you.

What was wrong with anyones advice here?

 

[altazi]

Hi Chookman,

I am not saying your (or anyone else's) advice was anything other than helpful. Have you visited (or posted) in the "Other: Other" forum? I was thinking that this might help our new visitor become better acclimated to the surroundings, and establish a more appropriate set of expectations.

Regards,

Altazi

 

[mlhm5]

I have ordered an EVGA 8800 witha power supply, but my ongoing research into upgrading pcs has led to some concern. The requirements for the card say a minimum 450 watt with minimum of 30 amps on the 12v rail. However, the psu I have coming has two rails one with 18amps and one with 20....is this psu going to work? Or does the GPU hook to only one rail, and therefore will be short on power?

Pick one from here. You have chosen unwisely.

http://www.jonnyguru.net/forums/showthread.php?t=1460

 

[altazi]

Stick with a single +12V rail; you won't get into trouble trying to balance the utilization on the multiple rails. Use a PSU calculator to give you a reality check. Hard to go wrong with a PC P&C Silencer 750 Quad.

 

[Zorg]

Hi Jdice1980,

Post your question in "The Other" forum. There are some very knowledgeable people there who will be happy to help you.

What was wrong with anyones advice here?

:lol: :lol: :lol:

 

[chookman]

Hi Chookman,

I am not saying your (or anyone else's) advice was anything other than helpful. Have you visited (or posted) in the "Other: Other" forum? I was thinking that this might help our new visitor become better acclimated to the surroundings, and establish a more appropriate set of expectations.

Regards,

Altazi

Heres me being really confused...