20 amp 12v line for 7600GT? Arggh.

[Markbnj]

So I put in an order for a BFG 7600GT last night, and then realized it calls for a 20 amp 12v rail. My Antex NeoPower 480 makes 18 amps on the 12v rail. I'm not sure whether all 7600's need 20, or just this BFG o/c'd model. Think I can get away with 18 amps? I browsed PSUs on Newegg and the vast majority seem to have 18 or 15 amp 12v rails. Do I need a $100+ PSU replacement to drive my $113 card?

 

[Accord99]

Xbitlabs measured <40W power consumption for the 7600GT.

http://www.xbitlabs.com/articles/video/display/power-noise_5.html

It doesn't even need the PCI-e auxillary power connector.

 

[Markbnj]

Thanks for the link... so... wow, that's like less than 4 amps. 40w/12v. Why the heck would they specifically call for a 20 amp 12v rail for this card? Anyway, makes me feel a lot better to read that review.

 

[F1shF4t]

Originally posted by: Markbnj
Thanks for the link... so... wow, that's like less than 4 amps. 40w/12v. Why the heck would they specifically call for a 20 amp 12v rail for this card? Anyway, makes me feel a lot better to read that review.

They specify that for the whole system, chances are that people who get a card like that have a good system to go with it. For example the estimate of 20amps on the 12volt rail for 7800gt or something like that they give is an underestimate for my system, it will prolly blow up that psu if i tried to use one. (mine has 30 amps, and the 12v rail get quite a voltage droop at full load)

 

[Markbnj]

Ah, I got you. That makes sense, thanks. I was running a 6800GT before, with the aux. power connector, so according to this pseudo-logic I should be ok.

 

[akshayt]

20A is for the whole system under all the rails. The card shouldn't be needing more than 7A, infact this card may only need around 4A!

 

[Markbnj]

Yeah, I'm thinking less than 4 amps. But I am curious to go around to spec sheets and add up the power draw on my system. I don't have that much in it, but I do have two drives, the burner, Audigy, TV Wonder, and the X2. I always assumed I was fine with 480 watts, but now I'm wondering if I have been peaking past the 18 amps the 12v can supply. I have had lockups with the graphics card, only in certain games, since I built the system, and have assumed it was the infamous nVidia nv4_disp.dll problem. That's one of the reasons for getting off the 6800GT and onto a 7 series PCIE solution: to see if it goes away. 18 amps sounds like a crapload of power to me.

 

[Captante]

If you were running a 6800GT without problems, then you won't have any trouble with the 7600GT because it uses a lot less power.

 

[brikis98]

to add to what others have said, if this is your PSU, then you actually have dual +12V rails (18A and 15A). although they don't necessarily add up directly, you have much mroe than 18A on your +12V total

 

[Markbnj]

Originally posted by: Captante
If you were running a 6800GT without problems, then you won't have any trouble with the 7600GT because it uses a lot less power.

Well, I was having problems in certain games, but it looked a lot like a well-known, but poorly understood, infinite loop issue with nVidia cards. That's why I was investigating power draw, just in case it actually was a power issue and my diagnosis was mistaken. I wasn't able to find complete power consumption data for most of my components, but I did run across this article from SilentPC last year. They measured the total draw of six systems under various conditions, and none of them drew more than 13.5 amps on the 12v rail.

to add to what others have said, if this is your PSU, then you actually have dual +12V rails (18A and 15A). although they don't necessarily add up directly, you have much mroe than 18A on your +12V total

Yep, that's the unit, and I think that's a good point too. I don't think I have a power issue. Thanks guys.

 

[aka1nas]

That would be >=20A if your PSU has a single +12V rail.