Selecting the default GPU on an Asus motherboard

07
2014-07
  • F.X.

    I have an ASUS P9X79 motherboard, on which I originally had one GPU (a cheap nVidia GeForce 210). I recently bought a newer, better GPU, and inserted it into the second PCI-E slot on the motherboard.

    The new GPU is recognized by Linux but not by the BIOS - lspci and the nVidia control panel both show the 2 GPUs if I keep my monitors on the old one, but the monitors stay blank if I plug them into the new GPU.

    I tried swapping both GPUs to see if the motherboard defaulted to the GPU on the first slot, with no avail : the video output stayed on the old GPU.

    Is there a hardware switch or a hidden option in the BIOS setup menu that would let me change the default GPU?

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    Related Question

    boot - Asus P8P67 Rev. 3.1 Motherboard issues powering on and saving settings
  • Scott

    Edit: New Information

    Have some updated information from the old question below:

    So basically my issue right now is somewhat similar, but I've been able to rule out a couple of things. I don't think this has anything to do with light on the motherboard. No matter what lights are on/off on the motherboard when the computer is off, they don't affect this issue. The main power LED on the Mobo is always lit when the power supply is turned on, and that's what matters anyway.

    Even when the main power LED is on, the PC will NOT boot up the first time I hit the power switch. I have to go reset the power supply (make all lights turn off on the Mobo and back on), and THEN hit the power switch. Then everything boots up. Also, the BIOS settings are reset every time this happens.

    Asus Tech Support told me to try jumping the power with something metal to try and rule out that it's a problem with the connectors getting power, or if it's a problem with the case power switch pins - haven't done that yet though.

    Any ideas? This is a lot simpler than it was before when I thought it had to do with certain LED indicators for RAM, EPU, etc.

    Original Question

    So I built my new desktop just about 3 weeks ago. I've been having a few issues which I think are all related to my motherboard, an Asus P8P67 Revision 3.1, but I'm not 100% sure as this is really the first from-scratch build I've ever done.

    I've posted these questions on the Asus forums, Asus Tech Support, and the Corsair forums as well as I thought it might have something to do with my power supply at one point. None of these avenues have solved my issue until now completely, so I thought I'd come here to see what you guys think.

    Here's what's happening:

    1. My computer is off, and I go to power it on. I press the power switch on the case (Antec Nine Hundred), and nothing seems to happen. Upon further inspection, I see that what this actually does is simply turn on the EPU LED on my motherboard, but doesn't actually boot anything up.
    2. I then have to go and flip the main power switch on the power supply off and back on. What this does is turn off all lights on the Motherboard after a few seconds, and turn them all back on (including the EPU LED that was off before I hit the power switch the first time).
    3. Now, hitting the power switch works. The machine boots up fine, and starts going through the boot up process.

    As a side note: My Motherboard is set to "Force BIOS", and every single time I change this to do the opposite, the next time my computer boots up that change reverts itself. I think this may be due to the fact that I am doing the hard reset on the power supply each time, but I'm not sure. I had thought that the Motherboard would keep its BIOS settings unless you did something to the Mobo itself - so this may be a related issue, or something else completely.

    That's basically it. Once it's on, it's on. It works fine, recognizes all of my hardware, and runs great. All fans/lights in the case work great, and I'm getting standard readings. The next time I go to shut the computer down however, I can expect the same exact process getting it up and running, including being forced to go into BIOS and exit again before I can load Windows.

    Another side note: If I power on my computer using the power switch DIRECTLY after shutting it down, it powers right back on (I think this is because the EPU LED light doesn't have time to turn off). It looks as if as long as the EPU LED is lit up on the motherboard before I hit the power switch on the case, the thing will boot up fine (although this doesn't explain the "Force BIOS" issue, at least it's something).

    Any ideas? Thanks guys.

    P.S. - System Specs

    • Asus P8P67 Rev. 3.1 Motherboard
    • Intel Core i7 2600K Processor
    • 16GB (4x4GB) G-Skill 1600 RAM
    • NVIDIA EVGA GTX 570 Video Card
    • Crucial 128GB SSD HD
    • Corsair 850W Power Supply
    • Seagate 2TB HDD

    • Related Answers
  • Nick2253

    To be honest, it sounds like you might have a defective motherboard. I'm not sure exactly what steps you've taken before, so I've listed a few diagnostic steps below, but feel free to ignore them if you've already done them.

    1. Update the BIOS.
    2. Replace the CMOS battery.
    3. Remove and reseat all components.
    4. Remove all components except for PSU, mobo, CPU, GPU (leave only 1 if you have SLI/CF), and RAM (leave only 1 stick), and see if the issue is still there.
    5. When the computer boots, run a memory test to see if there are any problems with the memory.
    6. Try a different PSU.
    7. Try all components with a different mobo.
  • soandos

    Solved: Updating to the last firmware and enabling "Power on by PCIe" cured the problem. See this.