darshie76
Level 1 (4 points)
Desktops

Q: how to use secondary video card on Pro 3.1

I did try to install a PC Radeon 5870 in a 3,1 mac Pro; and so far it seems to work (system info recognize it as Radeon 5000)

 

It won't show the boot screen, so to log in I still need to use the secondary monitor connected to the original video card (Nvidia Gt 120).

 

Although, when O launch a software, it seems to use the Nvidia card, since the performances are basically horrible.

Is there some action to take to force the OS to use the Radeon (which is on the main X16 slot)? I did check in the various options but I can't see anything that allow me to specify which one is the primary card.

Mac Pro, Mac OS X (10.7.3), 2.66 Quad x2, ATI Radeon 5870, 7 Gb

Posted on Aug 28, 2016 7:22 PM

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darshie76

Q: how to use secondary video card on Pro 3.1

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  • by lllaass,

    lllaass lllaass Aug 29, 2016 12:56 AM in response to darshie76
    Level 10 (187,626 points)
    Desktops
    Aug 29, 2016 12:56 AM in response to darshie76

    A PC graphics card unless flashed with Mac EFI firmware, will not show a boot screen.

    To flash your card see:

    http://forum.netkas.org/index.php/topic,692.0.html

  • by Johnb-one,

    Johnb-one Johnb-one Aug 29, 2016 12:02 PM in response to darshie76
    Level 4 (1,874 points)
    Desktops
    Aug 29, 2016 12:02 PM in response to darshie76

    to follow up, what IIIaass said is correct. With a PC card, you won't get a boot screen unless it has been flashed with Mac firmware, which I have no idea how to do, but others may. There is, as far as I know, no software to allow you to choose which graphics card to use and which set of drivers to load on bootup, also, there's no such thing as CrossFire on Mac (the ability to use two of the same kind of graphics card linked together for better performance) or 3d monitors

    (that I know about). Your Nvidia GT 120 might be old, but usable. Have you tried updating its software and cleaning it out of dust? if that still doesn't improve things, it might be time for you to consider getting a more modern,  beefier nvidia card (f that's what you prefer) . Otherwise, shut down,  remove the nVidia card, put the Radeon in the main X16 slot,  make sure the power cables (if needed) are connected, reboot, and hold down the cloverleaf, option, p and r keys for 3 "bongs" then release the keys and let computer continue to boot up as per normal.  Of course, there will be no boot screen, so you'll have to wait until the graphics driver loads, and you see a screen...

     

    good luck

    hope this helps you a little bit

    \John B