QUESTION: dual video triple monitor

We have quite a few extremely talented IT folks here and I am hoping someone can help me solve a problem that Gigabyte has no answer to.

I am running a Gigabyte  GA-X58A-UD3R(rev. 2.0) with 12Gb on 6x sticks of Corsair Ram. I have two video cards: a Gigabyte Radeon 6850 and Radeon 6870. There are no other plug in cards and I am using a single Crucial M4 256Gb Drive.  With a Corsair 750W power supply. Running Windows 7 64bit Ultimate.

I am wanting to use both videos cards in the system. Using the 6870 to drive a single monitor that I would use for gaming, and the 6850 to drive 2 monitors for work and applications. I can get the system to boot with either card but it fails to boot when both cards are inserted. I tried the cards 6870 in pcie 1 and 6850 pcie 2 and I have flipped them around and they both fail to boot with a beeping sound.

I have tried loading other OSes and putting in the cards with drivers loaded and without drivers loaded, but I am assuming there is an IRQ or some other collision occuring. I have also booted each card individualy in each PCIe slot.

Just for giggles and to rule out every possible issue I ran memtest x86 for 3 iterations and it found nothing, I ran several scans on the hard drive and it is also fine. I have tried booting with XMS enabled and disabled. I am not overclocking or using any custom multipliers. And no, I am not trying to run them in a CrossFire setup. 

I do not have another board to test this with but I am truly stumped. I have other online friends who are running similiar configs with different MB and video cards, but they are using 2 different cards with three monitors.

Any suggestions or advice would be greatly appreciated.

Cheers

That's odd, this should work. Windows 7 supports it and everything. "fail to boot with a beeping sound" -> I assume this means the system won't POST? It might be a problem with your PCI initialization order. According to your motherboard manual, this is in BIOS under "Advanced BIOS Features" -> "Init Display First". Try setting this to "PCIE x16-1". If that doesn't help, try "PCIE x16-2". Let us know what happens.

I had my bios set to use pcie-1, I moved it to pcie-2 and swapped the cards around without working. I upgraded my bios and can get it now work with it still on pcie-2 with the 6850 in the second slot. There are some weird resume from sleep video issues, but the system now boots! Thanks

Well, it sounds like a BIOS upgrade did the trick, more or less. For future FYI (and anyone else wondering) anytime you get a beep and failure to boot when powering on, it is a BIOS level problem, never the operating system or drivers. Usually the "beep" is a code that identifies the exact POST failure. The manual might contain a code index, but the motherboard manufacturer should know for sure. In this case, its isolated to the video cards and BIOS, nothing else. Also make sure your power supply can handle the load of both cards, if the primary card doesn't have enough juice, it can have a similar effect. "Underpowered/Going Bad" Power supplies are one of the main causes of "strange stuff" head-scratchers.

Thats a waste of a 6870 vidcard. In crossfirex configuration you'll only run as fast as the slower card, the 6850 in this case. The amount of ram you have by adding cards is good for multi-monitor at high resolutions. And both cards are driving all monitors not doing it seperately since I assume you are running crossfire mode? I'm running 24" monitors x 2 and a 24" LCD TV that I can switch for a 3rd desktop off a single 6850. No problems. Take that 6850 out, you're just pulling juice you don't need.

I don't think he's running crossfire, he's just purposing cards.

They are not in crossfire. As far as I know you can not run crossfire with 2x different cards. The 6870 is driving the monitor I use for gaming, the 6850 is driving the other 2 monitors that I use for 2d desktop work.