Dual Supplimental Power Connectors

[YoMoma]

Just bought a PNY 8800GTX XLR8 768mb card. Ready to install it but suprised to find that it has dual power connectors. (Dual supplimental Power Connectors). It appears I need to use 2 power connectors for this card. No problem, my power supply came with 2, for running SLI, but what am I to do if I want to run 2 cards? I only have 2 rails set specifically for PCI-E cards. Guess I will need a new power supply with 4 rails if I want to run SLI.

[Stormcrow]

Exactly, you'll need a PSU with quad PCI-E connectors in order to run two 8800GTXs. You could also use a couple of molex to PCI-E adapters, but this route is dangerous unless your sure that the PSU can handle the load of two of these beasts. The best route is just to get a beefer PSU with the connectors you need as you won't have to worry about which rails the load is on.

[Yellowhello]

Well, actually there are some PSU's with a single 12V rail, but with multiple PCI-E connectors. You would need a bigger PSU, you are right about that... what's the wattage on your current one?

[Stormcrow]

That's true, with a single rail you don't have to worry about balancing the load. Those PSUs are uncommon though, but you'll find some in the higher echelon on more prominent brands.

[fstroupe]

I suppose that is the main purpose for the Ultra Power Partner.

[YoMoma]

I`m using an Enermax Liberty 620 watt power supply. Should be enuf for the GTX card.

[Reloadron]

For what it is worth, the 8800 GTX with 768 MB or RAM will typically draw about 132 Watts under full load or about 11 Amps. The reasoning for the dual connector is from a current standpoint it is sort of unwise to run more than 7 Amps through a single connector. Yes, it would work but is not a good design practice. Therefore with two aux connectors each would typically draw less than 6 Amps.

The trick becomes making sure your PSU can deliver the needed 11 Amps from the rail with the connectors for the graphics card.

A pair of 8800 GTX in SLI (Same card X2) will draw about 246 Watts or about 10.25 Amps per card.

Now also in reality some of that power should be drawn through the PCI slot but it is best not to even figure that in.

I am not sure about how your PSU distributes power and damnit someone is at the door.

Ron