DMS-59 Dual Monitors - Dependent on installed slot?

[sgopalan78]

I have an HP dc7800 small form factor PC. It has two PCIe x1 and one PCIe x16 slots. Top to bottom it goes

PCIe x1
PCIe x16
PCIe x1

I have two lp GeForce 8400 GS cards - one x1 with a DMS-59 port and one x16 with a DVI port.

When I install the card with DMS-59 in the top x1 slot - I can drive two monitors off of it.
Due to logistics I cannot install the card with DVI while the first x1 slot is taken.

So I moved the DMS-59 card to the third slot and put the DVI card in the only x16 slot.

And now the DMS-59 card does not drive the second monitor (via a DMS-dual VGA cable) - only one will work.

What gives?

When I remove the DVI card from the x16 slot, the DMS-59 is once again able to light up both monitors - and it's still sitting in the third slot.

 

[borisof007]

I am guess you're trying to run 3 monitors?

I believe with Nvidia cards you can only run 3+ monitors while in SLi, so if your cards aren't in SLi mode (for which I don't believe your two different cards are capable of doing), it won't work.