SLI not showing up on my new EVGA x79 Dark mobo

[AzureAbyss]

Just got my new mobo in and installed everything. But my 2 titans are not showing up in SLI configuration. They each work individually when i try them by themselves. but when i put them both in and put the SLI bridge on. it still only shows up as having one card. I'm beginning to think i may not have a big enough PSU.

my build is the mobo as stated in the title
2 evga gtx titans
32 gb 2400 ddr 3 ram
3930k processor
750 watt psu

 

[skythra]

Just got my new mobo in and installed everything. But my 2 titans are not showing up in SLI configuration. They each work individually when i try them by themselves. but when i put them both in and put the SLI bridge on. it still only shows up as having one card. I'm beginning to think i may not have a big enough PSU.

my build is the mobo as stated in the title
2 evga gtx titans
32 gb 2400 ddr 3 ram
3930k processor
750 watt psu

A titan uses around 300 watts each, your CPU another 150 and you're out of power. Not to mention you should always overspec your powersupply as peak draw can jitter well above those numbers on any individual device, even if most of the time these parts use lower power than that.

Check your bios, check your SLi bridge (the strip on top of the cards connecting them).

Most graphics cards will represent their power state with a series of LED's and which would indicate if the cards aren't receiving enough power.

When you go to device manager can you see both cards? If you can but the nvidia properties don't let you enable SLi they could be underpowered. Or as above the Bios on your motherboard, or your SLi bridge needs investigating. If there is no second card in device manager, then again bios, reseat the video card, etc. If it's unknown, just reinstall the latest nvidia drivers.

Goodluck.

 

[ko888]

For a system using two GeForce GTX TITAN graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 850 Watt or greater system power supply that has a maximum combined +12 Volt continuous current rating of 60 Amps or greater and that has at least two 6-pin and two 8-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous Power/Current Available on the +12V Rail(s) rated at 45°C - 50°C ambient temperature, is the most critical factor.

Overclocking of the CPU and/or GPU(s) may require an additional increase to the maximum combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock. The additional amount required will depend on the magnitude of the overclock being attempted.

Did you plug in a 6-pin PCI Express supplementary power connector from the PSU into the motherboard's PCI-E SLI POWER connector?

 

[jitpublisher]

Just got my new mobo in and installed everything. But my 2 titans are not showing up in SLI configuration. They each work individually when i try them by themselves. but when i put them both in and put the SLI bridge on. it still only shows up as having one card. I'm beginning to think i may not have a big enough PSU.

my build is the mobo as stated in the title
2 evga gtx titans
32 gb 2400 ddr 3 ram
3930k processor
750 watt psu

This may sound sort of dumb, but you did not say whether you enabled SLI under the nVidia Control Panel, I am assuming you did that? (sorry, but I like to start simple and go up from there)