thedarkwolf25

Ok this is going to sound very noobish of me but I would rather look a fool than waste money or kill a part.

I am currently running a BFG Geforce 7950 Video card LINK
My power supply is a 500W Rosewill PSU LINK
I want to run an EVGA 8800GTS LINK or better.

My problem is that I don't really understand the whole amp per rail deal. My current PSU says that it has only 16A (I think I am reading that correctly) yet I am running a video card that requires 22A. Am I missing something? It just doesn't "click" for me.

I am really looking forward to playing Aion soon and I want to upgrade my Video card in preparation for it. But I am unsure of what my PSU can handle or if I will have to upgrade my PSU as well (which I really can't afford).

Any help would be greatly appreciated. Thanks!

manic

Not a foolish question, and it can be very confusing..The psu you have
has 2 12volt rails, a 16amp, and a 15amp if my memory serves. It
didnt list the efficiency, but its probably low. I would not use that
psu with the 8800***, or any pci-e vid card for that matter, not a
very high quality one. You could use the corsair 650watt, or for a few
bucks more the corsair 750watt. Stick with a quality psu, not a cheap
paperweight that will fry your components..

thedarkwolf25

Ok I have one more question, does that mean that it can only deliver 15A per rail? or can it deliver more than that if I am only using one 6-pin connector?

I want to at least look at a possible 9800GT but I won't be able to get that AND a new PSU. The 9800 requires 26A and at least a 400W. I have that but it's the Amps that I am concerned about, since my PSU says 15A and 16A I am wondering if it will add those 3 together and run that to the card, or will the card only receive the 15 or 16 Amps?

manic

The six pin, and eight pin connectors are pci-e connectors, expressly
made for the video card, a souped up power line if you will. To a degree
the rails are combined. There is some sort of formula for it. You cant
get away with a six or eight pin adapter, or I should say you shouldnt.
Sometimes they work, but imo I wouldnt use it, even though most
video card makers supply the thing. I recommend at least 26amps on
the 12volt rail/s no matter what the manufacturer says for pci-e
vid cards.
In considering a psu, you also have to take in the quality, and the
efficiency of the unit. And the age, with time psu's get weaker.

thedarkwolf25

Ok you say 26amps on the rails, but since my PSU has 2 12v rails does that mean that they have 16amps or a total of 31amps?

I guess what I am asking is when a card says that it needs say 26amps on the 12v rail is it refering to a single rail or all the 12v rails together?

manic

They are combined...But I dont think its totally combined, there is
some sort of formula...There is a sticky thread in the building section
of this forum that goes through at length on the subject,,,you might
want to take a gander at that, explains it alot better than I....

thedarkwolf25

Ok that helps a little, I know that I am due for a PSU upgrade just from the age of mine (I think it's around 3 years old now) but due to schooling and unemployment my cash flow is very limited. So I really want to see what my options are. Thanks for the help, I really appreciate it!