Dual Monitor Issues R9 290x

[gateway69]

So, I finally got Yosemite working on my old ex58-ud5 motherboard with a radeon 290x and have almost everything working but when I plug in another monitor I just get two black screens and it never displays the Yosemite desktop, even when I have Yosemite up and running on one and plug in the 2nd monitor both to black.

Anyone have any ideas on how to fix this?

I ran the Lux Mark benchmark tool and here are my results, I have no idea if thats good or bad..

 

[fotex]

i have same problem on r9 270x.
When i plug in only one display to hdmi everything works fine.
When i plug in second display to DVI Yosemite not start. Stuck on boot.

In Mavericks dual displays works fine too.

 

[carpentryplus25]

For some reason some of the smbios have been whitelisted and some features won't work with them in Yosemite like I couldn't get dual monitors working with an iMac definition and had to use a Mac pro 3,1 so try that out

 

[fotex]

i have "MacPro3,1"

Dual not work

 

[matfortu]

i solved using this config with clover:

http://www.tonymacx86.com/yosemite-desktop-support/144914-msi-r9-270x-dual-monitor.html

 

[fotex]

i solved using this config with clover:

http://www.tonymacx86.com/yosemite-desktop-support/144914-msi-r9-270x-dual-monitor.html

Do you install Yosemite with chimera or clover bootloader?

Give me please link to the installation instructions which you used

 

[matfortu]

Do you install Yosemite with chimera or clover bootloader?

Give me please link to the installation instructions which you used

I installed using the chimera usb stick (http://www.tonymacx86.com/445-unibeast-install-os-x-yosemite-any-supported-intel-based-pc.html) and on the first boot, instead of installing chimera through multibeast, i installed clover and put all the needed kexts (ethernet and fakesmc in my case) and config.conf in the efi partition that clover shows after its own installation.

 

[gateway69]

I tried a few things today w/o much luck. ill try clover also, but last week I did this and ran into constant rebooting when it booted into Yosemite

 

[fotex]

still does not work a second screen connected to the dvi-d

 

[gateway69]

im still fiddling with this, i might just try one dvi and one display port to see if it works..