Powering two 9800GTX GPUs - enough connectors?

[John Hewat]

This is my power supply:

An Antec 1000W which apparently has:

2 x 8-pin PCI-E connectors and 2 x 6-pin connectors for PCI-Express graphics cards

What does that mean about powering dual 9800GTX cards, which require 2 x 6-pin connectors per card?

Am I simply out of luck? Or can you get some sort of adaptor?

I have two 7800s plugged in at the moment, both of which require a single plug each; and that plug comes from inside the PSU... so I don't know how to go about attaching an additional pair of plugs for the upgraded cards...

[Jack Zhang]

Is your motherboard SLI compatible?

and 1000W is more than enough for 2 video cards.

There is a smaller PCI-e 1x like port on top of the card and that can be connected in SLI to boost performance compared to if they aren't connected.

You're issue is the amount of cables. There are always adapters included in the box of these video cards to convert 2 standard HDD power cables into 1 6-pin PCI-E and if you buy 2 cards, you get 2 of them for use on one card.

I also understand that your power supply is modular, meaning you can use less cables. with the use of 4 standard HDD ports, you should be fine since your HDD and disc drive should be powered by SATA anyways.

[John Hewat]

Originally Posted by Jack Zhang

Is your motherboard SLI compatible?

and 1000W is more than enough for 2 video cards.

There is a smaller PCI-e 1x like port on top of the card and that can be connected in SLI to boost performance compared to if they aren't connected.

You're issue is the amount of cables. There are always adapters included in the box of these video cards to convert 2 standard HDD power cables into 1 6-pin PCI-E and if you buy 2 cards, you get 2 of them for use on one card.

I also understand that your power supply is modular, meaning you can use less cables. with the use of 4 standard HDD ports, you should be fine since your HDD and disc drive should be powered by SATA anyways.

I don't know if the board is SLI compatible, but I don't care - I want the dual cards for 4 monitors rather than SLI.

So basically all I need to do is plug plugs out of the PSU together until I have enough plugs leading into the GPUs?

I have two of these ports (pictured left) just sitting in the case doing nothing, so if I can convert them into a single PCI-E power cable, and I use the two that are already in there, I'm still one cable short!

Second picture is the back of my power supply and neither of the two red ports on the left are being used at the moment - they are just empty. Are they options? I don't know what they are.

This is from a review of the PSU which makes no sense to me but may add to those trying to understand it:

The sleeved cables will help with airflow, and the modularity of the power supply will help with cable management. The modularity is arranged with four regular spots and two spots meant for 6-pin PCI-Express cables. These last two spots can be replaced with regular cables if needed. Some of the cables are not modular-they are wired into the unit in the regular fashion. The connectors include one 20+4 pin motherboard connector, one 12V EPS connector, one 12V ATX connector, two 6+2 pin PCI-Express connectors, two 6 pin PCI-Express connectors, eight SATA connectors, nine 4 pin device connectors, and two floppy connectors.

[John Hewat]

Those who own a nVidia GeForce 8800 GTX (or two, or four) considering the line should be very careful to get the second revision of the line. The first revision has some kind of bug that make nVidia's Power Sentry alarm go off on every boot and underclock the GPU. The system is usable, but graphics performance suffers greatly. The driver thinks that the card is not getting sufficient power when it actually is. The problem is in the PSU, not the card or drivers. Antec will happily replace first revision units that may still be in the wild.

How will I know if I have one of the 'first' units with the error? And does anyone know if this affects all nVidia cards or just the 8800s?