TWO video card (not SLI) can't work together?

WhiteFireDragon

WhiteFireDragon

New Member
i have a 7900gt 512mb currently running in my comp. i want dual monitors but the 2nd monitor uses VGA plug and i don't have the DVI to VGA adapter (YET). i put in my really ancient ATI 8mb video card in so that the VGA monitor can be plugged into something.

the problem is that when both cards are installed, my 7900gt stops working and the crappy ATI 8mb becomes the primary. is there some kind of setting i have to change to get them to both work? or is it that PCIe and PCI video cards both installed will not be compatible?
 
well i just partially figured it out. there is a setting in the bios to set first video boot to be PCIe or PCI, so i got my 7900gt working. but i guess just using both video cards on the same mobo won't work
 
yeah, I believe you have to two have two cards using the same form factor (pci or pcie) to work correctly. Im not entirely sure, but I remember seeing something about that on another forum post a while back.
 
Old ATI Cards don't always work in a multi-graphics card system because of drivers issues.

I tried using a ATI 9000, that didn't work. I contacted Nvidia, they said the PCI version of the 6200 would work, it did perfectly.

If you're feeling lucky, read this:
Ultramon FAQ said:
Secondary card doesn't work with Windows 2000/XP
Try the following:

1. set the secondary card as primary in the BIOS. If you have an AGP and a PCI card, look for a BIOS setting that lets you select whether AGP or PCI should be initialized first (more information). If you have two PCI cards, you need to swap them
2. go to Display Properties, and set the card of your choice as primary. The primary card should be your better card, as it is the one that will have accelerated 3D graphics and will be used by games

This workaround should work fine with older S3 and ATI cards, which need to be booted as primary because they need access to the VGA BIOS. If you have more than one card with this requirement, you'll have to replace all but the first one as only one card can be primary in BIOS. See the shopping guide for some suggestions for secondary cards.

Here's what Steve Deng from Microsoft told me on the issue: 'Win2k doesn't support this card as secondary adapter because this s3 device needs to access vga registers and call int10. These behaviors conflict with the primary video adapter. Although there might be ways to hack the problem, Win2k doesn't implement those approaches.'

If the secondary card still doesn't work, you will need to make it primary in Windows as well. SOURCE
Click to expand...

In short, have your computer boot on the ATI to possibly avoid the driver issues, and through windows, activate your other screens, and just make sure that the "primairy display" is set to a monitor connected to your more powerful card.
 
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i already tried setting the PCI as primary. when i do that and try to change the display settings, it says that the 7900gt is "not compatible because it was designed for an older version of windows." then nothing displays on the monitor that the 7900gt is connected to.

oh well... doesn't really matter because i'm getting the DVI to VGA adapter in a few days anyways...
 
WhiteFireDragon said:
i already tried setting the PCI as primary. when i do that and try to change the display settings, it says that the 7900gt is "not compatible because it was designed for an older version of windows." then nothing displays on the monitor that the 7900gt is connected to.
Click to expand...


Yes I recognized that, lol. I had my PC boot on my 7950GT, and it said exactly that for that Radion I was talking about.

I contacted ATI, and they just said that what I was doing is not recommended (WOW BIG HELP!!!), so I returned the card and contacted Nvidia. I asked what PCI card I could use along my 7950GT without driver issues. They answered me and said the PCI version of the 6200 will work, with no driver issues. So I bought that and it work flawlessly, yay NVIDIA! I'm very impressed by Nvidia's drivers, the "Nvidia Panel" seem to fully support multiple GPUs (Meaning not just for SLI, but also a mix of Nvidia Cards for multi-display purposes)

Now I can enjoy my triple display system!

WhiteFireDragon said:
oh well... doesn't really matter because i'm getting the DVI to VGA adapter in a few days anyways...
Click to expand...

Oh, you where trying to connect only two monitors? Your 7900GT will handle both quite effortlessly.
 
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sniperchang said:
Oh, you where trying to connect only two monitors? Your 7900GT will handle both quite effortlessly.
Click to expand...

lol yeah i was only trying to get dual monitor. i was lazy to go out to buy just the adapter, but i had an old ATI card laying around so i thought i was going to try that first. it ended up just making me frustrated because i thought i somehow broke my 7900gt while playing around with everything
 
oh yeah and there were 3 different adapters. i think mine is the DVI-I one. but would it still be ok if i bought the DVI-A or DVI-D adapters? what is the difference?
 
WhiteFireDragon said:
oh yeah and there were 3 different adapters. i think mine is the DVI-I one. but would it still be ok if i bought the DVI-A or DVI-D adapters? what is the difference?
Click to expand...

DVI-I means the output has Digital and Analog. So you can plug your LCDs to your graphics card that has DVI-I, or get a DVI to VGA adapter to plug in CRTs or LCD that have only VGA inputs (Because VGA uses analog signals, as opposed to digital for DVI connections).

DVI-A means that your graphics card only outputs analog
DVI-D is digital only, so little DVI to VGA adapters won't work with graphics card that have DVI-D.

The DVI to VGA adapter works with DVI-I, DVI-A, but not DVI-D.
 
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