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citizen513
May 8th 07, 10:34 AM
Question:

I am planning to buy an 8800 gts,
but my PSU doesn't have an extra PCIE power connector.

The card (XFX) doesn't provide one in the bundle.

I can buy a molex adapter but there are a few variants,
some have only 3 wires connected to the plug, others have
two molex connectors flowing into one PCI-E.

Which one is right?

Can I damage the card if I connect either of those,
(PCI-E connector is identical on both versions)

Thanks.

Paul
May 8th 07, 01:19 PM
citizen513 wrote:
> Question:
>
> I am planning to buy an 8800 gts,
> but my PSU doesn't have an extra PCIE power connector.
>
> The card (XFX) doesn't provide one in the bundle.
>
> I can buy a molex adapter but there are a few variants,
> some have only 3 wires connected to the plug, others have
> two molex connectors flowing into one PCI-E.
>
> Which one is right?
>
> Can I damage the card if I connect either of those,
> (PCI-E connector is identical on both versions)
>
> Thanks.
>
>


Your first concern, would be whether the power supply
has enough amps on +12V, to power everything.

The 2x3 PCI Express connector here, is used to carry about 6 amps,
in round numbers. Some more current also flows through the PCI
Express slot connector pins (roughly 3.5A).

http://www.xbitlabs.com/articles/video/display/msi8800gts-640_6.html
http://www.xbitlabs.com/images/video/msi8800gts-640/8800gts_full.gif

Even one pin on the PCI Express 2x3 connector can carry six amps.
AFAIK, the PCI Express 2x3 is from the same family as the main
power connector (either 20 or 24 pin), and uses the same kind of
pins.

If I was purchasing an adapter for myself, I would use the
one with two Molex connectors. That gives you the equivalent of
two of three 12V pins. Which should be enough to do the job, and
do it safely from the connector's perspective.

But check the label on your PSU first. If your supply is some
old 12V @ 15A supply, then two thirds of it will be taken up
by the video card, leaving little for the rest. There are a
few old supplies that are a pleasant exception (like one that
gives 26A), but there is a lot more junk out there.

Paul

citizen513
May 8th 07, 01:54 PM
>
> Paul
>

Thanks Paul.