Network card only works when 1 GPU is installed

[ken92]

Specs:

MSI H97 Motherboard
GPU : Quadro K2200 & Gigabyte GTX 780Ti Windforce
PSU : EVGA 750W G2
Network card : Asus PCE N-15 Wireless
OS : Win 8.1

Problem :

I just got a 780Ti to install onto my quadro system for some rendering power. What happened is that with 2 cards, my pcie network card stop working! So i thought it was PSU problem and i upgraded from a cheap 600W psu to a evga gold 750w PSU but the network card still does not work.

However ,if i remove any one card, it works again! Ive tried reinstalling the drivers and tried swapping the quadro and 780ti at different location but it still does not work. Swapping the network card to different slot does not work either. It only works when only ONE gpu is installed?? Help!

 

[kanewolf]

I think it is a PCIe lane problem. Not enough to go around. Look at the block diagram for the H97 chipset -- http://www.intel.com/content/www/us/en/chipsets/mainstream-chipsets/h97-chipset-diagram.html There are only 8 PCIe lanes from the chipset. When you plug in the second graphics card there aren't any left for the NIC card.

 

[ken92]

[/spoiler]]I think it is a PCIe lane problem. Not enough to go around. Look at the block diagram for the H97 chipset -- http://www.intel.com/content/www/us/en/chipsets/mainstream-chipsets/h97-chipset-diagram.html There are only 8 PCIe lanes from the chipset. When you plug in the second graphics card there aren't any left for the NIC card.

Kanewolf thanks for replying ,

So it is the way the connection of lanes that are designed giving me a problem ? Although I can fit another pcie inside?

msi h97 website says it support crossfire so doesn't make sense that the network card reached out limited provided there's enough power 🙁

http://www.msi.com/product/mb/H97-GAMING-3.html#hero-specification

 

[kanewolf]

Crossfire has enough PCIe lanes to run one card as x16 and one as x8. That is ALL the PCIe lanes there are according to the Intel graphic I linked. That is my interpretation based on the block diagram and the symptom.