I purchased Visiontek's 3870 X2 Graphics card to go in a Biostar A770 A2+ motherboard. After installing the drivers the system repeatedly crashes just before windows finishes booting. Do I need to upgrade my motherboard now? I am at a loss for this incompatability.

Specs:
Operating System: Vista 64 bit
Motherboard: Biostar A770 A2+
Graphics: Visiontek 3870 X2
Ram: 4 Gig

POWERSUPPLY specs??

Ah forgot that one.

Power Supply: MODU 82+ EMD 625 AWT

so its a 625 Watt power supply? Should be okay. I would suspect the driver as an issue.

Yes the power supply is 625 Watt. The motherboard is not Crossfire or CrossfireX. It was my understanding that the advantage of the 3870 X2 was that you didn't need Crossfire to have the power of two cards.

Do you suggest using Visiontek's or ATI's drivers?

The 3870 X2 actually does use crossfire. There are two gpus on the card, and they are in a crossfire configuration. I might be wrong, but I believe that this card requires a crossfire motherboard. It would at least explain why you are having difficulties using the card.

As for the drivers, Visiontek does not have their own drivers. There may be a driver CD included in the package you received, which are the ATI drivers. If I am wrong about your motherboard requiring crossfire for the 3870X2, perhaps the newer drivers will work better. You can download them from ATI's website.

So the solution is to buy a new motherboard. Will a plain vanilla crossfire board be sufficient or do I need to purchase a Crossfire X motherboard?

You do not need a crossfire motherboard! ! ! ! !

It sounds like you don't have enough power or you didn't uninstall previous drivers.

Again you don't need a crossfire motherboard, I'm living proof of that.

I don't think you need a new motherboard. The 3870X2 is essentially "crossfire on a stick", in other words the crossfire is all on the PCB that houses the GPUs.
I may be wrong on that, so don't quote me, but I'm about 75% sure.

Did you plug in the power connectors to the card? Most cards draw more power than the PCI-e interface can supply to the card itself. I believe theres two connectors on the card.

And yes, a 625W PSU should be enough, however, how many amps are on the 12V rail? This is the critical thing about your PSU. If there aren't enough amps on the 12V then the card is hungry for power.

The power supply is up to 25 Amps on all three voltage rails with over current protection up to 35 A. The power supply was specifically made to run quad crossfire or SLI.

Initially I didin't uninstall the original graphics drivers. I restored the last good configuration and then uninstalled them before reinstalling the graphic drivers. The crashes resumed upon rebooting.

Should I let windows search the CD and instal the drivers for me? What would it mean if windows can't find the driver?

Alright so it seems that neither the motherboard or the power supply is the problem. That leaves a driver issue. Go to ATI's website and download the latest drivers for the graphics card. It should remove any other drivers that are currently in place as the new ones install. I have installed new ATI drivers without removing the old ones myself so it should not be difficult.

Do not need crossfire motherboard... the 9800GX2 doesn't need an SLI motherboard too..

if you are to uninstall old drivers, you should use the ATI Catalyst uninstaller to make sure nothing is left from previous installs. they made it for a reason

http://downloads.guru3d.com/download.php?det=1275

and just to sound smart, x) no you don't need a crossfire mobo, thats the beauty of the 3870x2. i know cuz i have one myself :]

Yes, it sounds to me like you have driver conflicts. Make sure you uninstall the old drivers before trying the new. I'd get the 8.4 directly from AMD/ATI and not bother with the drivers on the CD.

You do not need a Crossfire board for a 3870x2. I have the MSI and it's running cool, quiet and doing well in Oblivion and The Witcher, not as good in LOTRO (but still not too bad -- that game has issues with SLI too).

I'm using Vista 32 bit, so perhaps there are issues with Vista 64 drivers? Check the FAQ's on ATI's page to see if that's an issue.

the newest drivers are catalyst 8.5...its available on the ATI/AMD site itself, and should be available now on your makers of the 3870x2 as well. remember, use the ati catalyst uninstaller to make sure you get a clean unistall.