"larry moe 'n curly" <larrymoencurly@my-deja.com> wrote in message
news:1193316186.917692.9530@q3g2000prf.googlegroup s.com...
>
> JB wrote:
>> It seems like both industries operate in a vacuum.
>>
>> I looked at a video card whose requirement was "a 350 W PS with 22 A
>> available on the +12V rail".
>>
>> Most PS ratings that I checked are rated for a maximum of around 18A on
>> the
>> +12V rail regardless of the advertised power rating.
>>
>> Some have dual or triple +12V rails whose combined ratings may be 36A or
>> higher.
>>
>> So how do we make a determination as to what the video card really needs
>> and
>> how to provide it?
>
> The only reliable ways are by finding somebody who's taken actual
> measurements, or buy/steal a DC clamp-on ammeter and measure for
> yourself. Estimated or stated ratings can be way off, but fortunately
> they're almost always higher than the actual current consumption.
>
> Is it possible that the 22A @ +12V rating is for the whole PSU and not
> just for the rail that plugs into the graphics card? Because I
> thought that multi-rail +12V was introduced as a safety measure, to
> limit each +12V rail to 20A. Also experts like JonnyGuru.com have
> found that some PSUs, such as the Antec Trio (made by Seasonic), that
> are claimed to have double or triple +12V rails actually have only
> one, so there's no need to worry about the per-rail amp ratings.<


Yep..like I was saying to Kony, the disclosure is pretty sloppy across the
board.. I tried to get a schematic on an Antec years ago and it turned out
to be too secret for the unwashed masses. lol I can understand that but
would even a block diagram would tell you if each rail had separate feedback
control or whatever awithout disclosing anything proprietary.

Thanks for your input.